WO2000042008A1

WO2000042008A1 - New vitamin d analogs

Info

Publication number: WO2000042008A1
Application number: PCT/EP2000/000288
Authority: WO
Inventors: Antonio MOURIÑO MOSQUERA; Ana Isabel Gacio Fernandez; Christian Vitale; Jan-Paul Van De Velde; Jan Zorgdrager
Original assignee: Solvay Pharmaceuticals BV
Current assignee: Abbott Healthcare Products BV
Priority date: 1999-01-14
Filing date: 2000-01-12
Publication date: 2000-07-20
Anticipated expiration: 2001-07-14
Also published as: AU2291600A

Abstract

The invention relates to a group of new vitamin D analogs of formula (I), wherein R1 is a hydrogen atom or a hydroxy group, A and B represent hydrogen or methyl, or together form the methylene group, R2 is a group of formula (II), wherein R3 is a group -(CH2)n-C(R4)2OH, wherein n has the value 0, 1 or 2, and R4 is a straight, branched or cyclic alkyl group having 1-3 C-atoms, or the vinyl group, p is 1 (when the dotted line is a double bond) or 2. These new arocalciferols have valuable biological properties.

Description

New Vitamin D analogs

The invention relates to new vitamin D compounds, to methods of preparing these compounds and to their use in pharmacotherapy and cosmetics.

It is generally known, that vitamin-D compounds or vitamin-D related compounds

("vitamin-D analogs") have a strong biological activity and may be used in all those cases in which problems with the calcium metabolism play a part. A few years ago it was found that various active vitamin-D compounds also have other pharmacotherapeutic activities and may be used successfully, for example, for the treatment of certain skin and bone diseases, for cosmetic applications and for treating diseases which are related to cell differentiation, cell proliferation or imbalance in the immune system, including diabetes mellitus, hypertension and inflammatory diseases such as rheumatoid arthritis and asthma. In addition, these compounds may be used in various veterinary applications, and for diagnostic purposes.

Vitamin D compounds which are of interest for the above applications are hydroxylated vitamin D compounds, in particular vitamin D compounds hydroxylated in the 1a-, 24- and/or 25-positions. Further developments in the field of active vitamin D compounds are 19-nor-vitamin D compounds (EP-A-0387077) and C₁₈- modified vitamin D compounds (EP-A-0521550), preferably also hydroxylated in the 1a-position and optionally in the C₁₇-side chain. Other modifications of the C₁₇-side chain have been proposed, likewise to improve the intended activity and to suppress detrimental side-effects. Examples of modifications of the C₁₇-side chain are 22-oxa modifications (e.g. WO 90/09991), fluor substitutions, epoxy groups (e.g. WO

92/21695), etc. In addition certain compounds with elongated side chains (homo compounds) are disclosed in literature, e.g. in the US patents 5,030,772, 5,206,229 and 5,250,523 and in articles by Perlman et al. (Biochemistry 1990, 29, 190-6) and by Chodynski and Kutner (Steroids 1991, 56, 311-5). Perlman et al. describe the insertion of a trans double bond at C-22 of 24-homologated analogs. This double bond insertion, however, does not significantly affect the activities compared with the respective analogs with saturated side chain. It has appeared, however, that transposition of the double bond in the natural C-22 position to the C-24 position, as described by Chodynski and Kutner, does not result in the intended improvement in selectivity. Generally spoken, the above C₁₇-side chain modified vitamin D compounds are still not completely satisfactory as regards their selective activity, i.e. the intended activity without detrimental side-effects.

In J. Med. Chem 1991 , 34, p. 2452-2463 four vitamin D analogs having aromatic side-chain analogs (or arocalciferols) are described. The described compounds have a C-17 side-chain of the formula - CH(CH₃)-CH₂-C₆H₅, wherein the phenyl group is substited with m-OH, p-OH, m-CH₃ and m-C(CH₃)₂OH respectively.

In biological studies these four compounds have been compared with the known compound calcitriol (or 1α,25-dihydroxyvitamin D₃). It was found that in none of the tests these arocalciferols are better than calcitriol.

It is the objective of the present invention to provide a new group of vitamin D analogs, having interesting biological properties.

According to the present invention it has been found that 21 -nor vitamin D analogs of the general formula

wherein:

R., is a hydrogen atom or a hydroxy group,

A and B represent hydrogen or methyl, or together form the methylene group,

R₂ is a group of the formula (II)

wherein R₃ is a group -(CH₂)_n-C(R₄)₂OH, wherein n has the value 0, 1 or 2, and R₄ is a straight, branched or cylcic alkyl group having 1-3 C-atoms, or the vinyl group, p is 1 (when the dotted line is a double bond) or 2, have interesting biological properties. When the dotted line in formula (I) is a double bond between C₁₇ and C₂₀ both the E and Z isomers belong to the invention.

The above defined new 21 -nor vitamin D analogs are valuable compounds, which are promising as biologically active substances and may be used in the above mentioned pharmacotherapeutic indications, for example for the treatment of osteoporosis, renal osteodystrophy, osteomalacia, skin disorders such as psoriasis and other hyperproliferative skin diseases, eczema, dermatitis, myopathy, leukemia, breast and colon cancer, osteosarcomas, squamous cell carcinomas, melanoma, certain immunological disorders, and transplant rejections.

The new vitamin D analogs of the invention can be obtained according methods known for this type of compounds, for example as indicated in scheme 1 :

Scheme 1

Reaction step 2 gives an E/Z mixture of 4.4:1. If it is desired to prepare the Z- compound the mixture obtained after step 3 can be treated with 9-fluorenone in THF under the influence of light, giving a mixture wherein E/Z ratio is 1 :4.2.

The product obtained after step 3 (for the E-isomer) or the product obtained after this additional fluorenone treatment (for the Z-isomer) can be separated by means of colomn chromotography to afford the pure E- and Z-isomer resprectively.

To prepare corresponding compounds wherein C₁₇ and C₂₀ are linked by a single bond the product obtained after step 3 can be hydrogenated in a manner known oer se:

The so-obtained C₁₇-C₂₀-staturated compound can be reacted as indicated in the above steps 4 to 8.

For the preparation of compounds having formula (I) wherein R₃ represent a group of the formula

-CH₂-C(R₄)₂OH

wherein R₄ has the above meaning, the product obtained after step 2 (scheme 1 ) can be converted as follows:

The so-obtained compound B can be further reacted as indicated in steps 4 to 8.

According to reaction steps 1 to 8, and the optional steps for changing the E/Z-ratio and/or hydrogenating the C₁₇-C₂₀ double bond and/or introducing a group R₃ as indicated above, the compounds having formula (I) as defined above can be obtained.

The invention will now be described in greater detail with reference to the following specific Examples.

In the Examples and in the above mentioned reaction steps of scheme 1 the following abreviations are used:

Example 1

a) 4-bromobenzyl diethylphosphonate (scheme 1. step 1 :

The dibromide (7 g, 28 mmol) and freshly distilled P(OEt)₃ (4.65 g, 28 mmol) were added in a 50 ml_ round-bottomed flask, equipped with a magnetic rod and condenser with a tube of CaCI₂. The mixture was heated at 90-100°C for 7 h. The residue was purified by distillation (fraction 150-160°C, 10^"1 mm Hg), obtaining the phosphonate [6.8 g, 80%, colourless oil]. ¹H-NMR (CDCI₃, 250 MHz, δ): 7.40 (2 H, d, J= 8.3 Hz, H-Ar), 7.14 (2 H, dd, J_(H._P)= 2.2 Hz y J= 8.3 Hz, H-Ar), 3.99 (4 H, m, 2 [CH₃-CH₂-O]), 3.06 (2 H, d, _(H-P)= 21.7 Hz, Ar-CH₂-P), 1.22 (6 H, t, J= 7.1 Hz, 2 [CH₃-CH₂-O]). ¹³C-NMR (CDCI₃, 62. 83 MHz, δ): 131.2 (4 CH), 130.5 (C, d, J_(C._P)= 9.2 Hz), 120.6 (C, d, J_(C._P)= 4.5 Hz), 61.8 (2 CH₂, d, J_(C._P)= 6.7 Hz), 32.9 (CH₂, d,

J_(C-P)= 138.5 Hz), 16.1 (2 CH₃₎ d, J_(C-P)= 5.9 Hz). b) 8 β-tert.butyl dimethyl silyloxy -17 (E/Z)-[1-(4-bromophenyπ methylidene]-des- A. B-androstane (scheme 1. step 2 :

KH (0.76 g, 18.9 mmol) was dissolved in dry THF (20 ml) in a 100 ml round- bottomed flask, equipped with a magnetic rod and condenser with an argon supply. A mixture of the ketone (1.96 g, 6.93 mmol) and the phosphonate (6.39 g, 20.8 mmol) in dry THF (40 ml) was added, via a cannula, to the previous solution. The mixture was heated under reflux for 5 h. The reaction was stopped by addition of a HCI solution (5%, 5 ml). The organic phase was washed with H₂O

(30 ml) and dried, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (25 x 2.5 cm, eluent: 100% hexane) to give the E/Z mixture of the bromide [3 g, 99%, Rf_E = 0.6 and Rf_z = 0.7 (100% hexane), colourless oil].

¹H-NMR [£, 33p] (CDCI₃, 250 MHz, δ): 7.43 (2 H, d, J= 8.4 Hz, H-Ar), 7.19 (2 H, d, J= 8.4 Hz, H-Ar), 5.97 (1 H, s, H-20), 4.15 (1 H, m, H-8), 2.76-2.43 (3 H, m, 2 H-16, H-14), 1.15 (3 H, s, Me-18), 0.96 (9 H, s, f-BuSi), 0.10 (6 H, 2 s, Me₂Si). ¹³C-NMR [E, 33p] (CDCI₃, 62.83 MHz, δ): 157.15 (C), 137.8 (C), 131.2 (CH), 129.8 (CH), 119.2 (C), 115.4 (CH), 69.2 (CH), 50.5 (CH), 45.2 (C), 36.8 (CH₂), 34.6

(CH₂), 28.3 (CH₂), 25.8 (3 CH₃), 24.0 (CH₂), 21.5 (CH₃), 18.0 (C), 17.6 (CH₂), -4.9 (CH₃), -5.2 (CH₃).

¹H-NMR[Z, 52p] (CDCI₃, 250 MHz, δ): 7.35 (2 H, d, J= 8.4 Hz, H-Ar), 7.03 (2 H, d, J= 8.4 Hz, H-Ar), 6.10 (1 H, s, H-20), 4.06 (1 H, m, H-8), 2.69-2.29 (3 H, m, 2 H-16, H-14), 1.24 (3 H, s, Me-18), 0.90 (9 H, s, t-BuS ), 0.03 (3 H, s, Me₂Si),

0.02 (3 H, s, Me₂Si). ¹³C-NMR[Z, 52p] (CDCI₃, 62.83 MHz, δ): 155.3 (C), 138.0 (C), 131.12 (CH), 130.5 (CH), 119.7 (C), 117.7 (CH), 69.7 (CH), 52.6 (CH), 44.5 (C), 37.2 (CH₂), 34.2 (CH₂), 31.1 (CH₂), 25.8 (3 CH₃), 23.0 (CH₂), 20.6 (CH₃), 18.0 (C), 17.5 (CH₂), -4.9 (CH₃), -5.2 (CH₃).

c) 8 β-tert.butyl dimethyl silyloxy-17(E/Z)-[1-[4-methoxycarbonyl. phenyQmethylidene] des-A. B-androstane (scheme 1. step 3)

The bromide (1.85 g, 4.24 mmol) was dissolved in dry DMSO (70 ml) and dry MeOH (25 ml) in a 250 ml round-bottomed flask, equipped with a magnetic rod and condenser with an argon supply. Dry Et₃N (543 μl, 4.24 mmol), dppp (385 mg, 0.93 mmol) and Pd(OAc)₂ (191 mg, 0.85 mmol) were then added. The suspension was purged with CO and stirred at 80°C in an atmosphere of CO for 16 h. The reaction was stopped by addition of H₂0 (40 ml). The aqueous phase was extracted with EtOAc (3 x 20 ml). The combined organic phases were washed with H₂O (3 x 20 ml), dried, filtered and concentrated under reduced pressure. The residue was purified by rapid column chromatography (15 x 3.5 cm, eluent: 100% hexane) to give the ester.

¹H-NMR (CDCI₃, 250 MHz, δ): 7.98 (2 H, d, J= 8.34 Hz, H-Ar), 7.36 (2 H, d, J= 8.39 Hz, H-Ar), 6.05 (1 H, s, H-20), 4.11 (1 H, m, H-8), 3.90 (3 H, s, MeO), 2.77-2.51 (3 H, m, 2 H-16, H-14 ), 1.13 (3 H, s, Me-18), 0.93 (9 H, s, f-BuSi), 0.06 (6 H, s, Me₂Si). ¹³C-NMR (CDCI₃, 62.83 MHz, δ): 167.04 (C), 159.3 (C), 143.5 (C),

129.5 (CH), 127.9 (CH), 126.9 (C), 115.9 (CH), 69.1 (CH), 51.8 (CH), 50.4 (CH₃), 45.4 (C), 36.7 (CH₂), 34.5 (CH₂), 28.6 (CH₂), 25.8 (3 CH₃), 24.0 (CH₂), 21.5 (CH₃), 18.0 (C), 17.6 (CH₂), -4.84 (CH₃), -5.2 (CH₃).

d^ 17 (EHH4-(methoxycarbonyl)phenyl]methylidene] des-A. B-androstane-8β-ol

(scheme 1. step 4)

The ester (96 mg, 0.23 mmol) was dissolved in acetonitrile (2.5 ml) in a 5 ml round-bottomed flask, equipped with a magnetic rod. An aqueous solution of HF (48%, 15 drops) was added, to the solution and the mixture was stirred at room temperature for 2 h. The reaction was stopped by addition of a saturated solution of NaHC0₃ (2 ml). The aqueous phase was extracted with Et₂O (3 x 5 ml). The combined organic phases were washed with H₂0 (10 ml) and dried, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (15 x 1.5 cm, eluent: 30% Et₂0/hexane) to give the alcohol [66 mg, 96%, Rf = 0.32 (40% Et₂0/hexane)].

¹H-NMR (CDCI₃, 250 MHz, δ): 7.96 (2 H, d, J= 8.2 Hz, H-Ar), 7.35 (2 H, d,

J= 8.15 Hz, H-Ar), 6.05 (1 H, s, H-20), 4.19 (1 H, m, H-8), 3.88 (3 H, s, MeO), 2.80-2.52 (3 H, m, 2 H-16, H-14), 1.14 (3 H, s, Me-18). ¹³C-NMR (CDCI₃, 62.83 MHz, δ): 167.0 (C), 158.5 (C), 143.2 (C), 129.4 (CH), 127.8 (CH), 126.8 (C), 116.1 (CH), 68.7 (CH), 51.8 (CH), 49.9 (CH₃), 45.0 (C), 36.4 (CH₂), 33.8 (CH₂), 28.5 (CH₂), 23.5 (CH₂), 21.1 (CH₃), 17.3 (CH₂).

e) 17 (EV[1-[4-(methoxycarbonyπphenyl3methylidene]des-A. B-androstan-8-one (scheme 1. step 5)

The alcohol (163 mg, 0.54 mmol) was dissolved in dry CH₂CI₂ (25 ml) in a 50 ml round-bottomed flask, equipped with a magnetic rod. PPTS (catalytic) and PDC (307 mg, 0.82 mmol) were successively added to the solution with stirring. The reaction mixture was stirred under argon with light excluded for 14 h. The mixture was filtered through a No. 4 filter plate, equipped with a layer of Celite, washing the solids with CH₂CI₂. The residue obtained after concentration under reduced pressure was purified by rapid column chromatography (20 x 1.5 cm, eluent: 40% Et₂0/hexane) to give the ketone [147 mg, 91 %, Rf = 0.4 (40% Et₂0/hexane), colourless acid].

¹H-NMR (CDCI₃, 250 MHz, δ): 7.96 (2 H, d, J= 8.3 Hz, H-Ar), 7.35 (2 H, d, J= 8.4 Hz, H-Ar), 6.17 (1 H, s, H-20), 3.87 (3 H, s, MeO), 0.84 (3 H, s, Me-18). ¹³C-NMR (CDCI₃, 62.83 MHz, δ): 210.7 (C), 166.8 (C), 155.3 (C), 142.3 (C), 129.4 (CH), 128.0 (CH), 127.4 (C), 117.8 (CH), 58.8 (CH), 52.1 (CH₃), 51.9 (C), 40.9

(CH₂), 35.0 (CH₂), 28.3 (CH₂), 23.4 (CH₂), 20.4 (CH₂), 19.5 (CH₃). f) tert.butyl dimethyl silyl ether of (17E)-1α-tert. butyl dimethyl silyloxy-20-[4- (methoxy-carbonvhphenyl]-17.20-didehydro-21.22.23.24.25.26.27-heptanor-vitamin D₃ (scheme 1. step 6)

The phosphine oxide (234 mg, 0.402 mmol) was dissolved in dry THF (5 ml) in a

25 ml round-bottomed flask, equipped with a magnetic rod and a septum. A solution of n-BuLi in hexane (161 μl, 0.362 mmol, 2.25 M) was added slowly to the solution cooled to -78°C, upon which an intense red colour developed. A solution of the ketone (60 mg, 0.201 mmol) in dry THF (2.5 ml) was added slowly, via a cannula, to the mixture which was additionally stirred for 1 h. The solution was stirred for 4 h with light excluded and it was then allowed to rise to -40°C over 2 h. The reaction was stopped by addition of H₂0 (5 ml). The aqueous phase was extracted with Et₂0 (2 x 15 ml). The combined organic phases were washed with a saturated solution of NaCI (15 ml), and dried, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (12 x 1.5 cm, eluent: 2-80% Et₂0/hexane) to give the desired compound [116 mg, 89%, Rf = 0.83 (20% EtOAc/hexane), colourless oil].

¹H-NMR (CD₂CI₂, 250 MHz, δ): 7.94 (2 H, d, J= 8.3 Hz, H-Ar), 7.39 (2 H, d, J= 8.3 Hz, H-Ar), 6.28, 6.12 (2 H, AB, J= 11.1 Hz, H-6 y H-7), 6.15 (1 H, s,

H-20), 5.21 (1 H, s broad, H-19_ε), 4.88 (1 H, s broad, H-19₂), 4.40 (1 H, m, H-1 ), 4.20 (1 H, m, H-3),3.86 (3 H, s, MeO), 0.88 (9 H, s, f-BuSi), 0.88 (9 H, s, f-BuSi), 0.74 (3 H, s, Me-18), 0.08 (6 H, s, Me₂Si), 0.07 (6 H, s, Me₂Si). ¹³C-NMR (CD₂CI₂, 62.83 MHz, δ): 167.6 (C=0), 159.4 (C), 149.2 (C), 144.1 (C), 140.6 (C), 136.7 (C), 130.2 (2 CH), 128.7 (2 CH), 128.0 (C), 123.7 (CH), 119.4 (CH), 118.1 (CH), 112.0

(CH₂), 72.8 (CH), 68.3 (CH), 54.6 (CH), 52.6 (CH₃), 49.5 (C), 46.8 (CH₂), 45.6 (CH₂), 37.4 (CH₂), 30.0 (CH₂), 29.6 (CH₂), 26.4 (6 CH₃), 24.1 (CH₂), 24.1 (CH₂), 19.5 (CH₃), 18.9 (C), 18.8 (C), -4.1 (CH₃), -4.2 (CH₃), -4.3 (CH₃), -4.5 (CH₃). g) tert. butyl dimethyl silyl ether of (17E)-1α-tert. butyl dimethyl silyloxy-20-[4- (dime-thylhvdroxymethvnphenyl]-17.20-didehydro-21.22.23.24.25.26.27-heptanor- vitamin D (scheme 1. step 7)

The ester (59 mg, 0.089 mmol) was dissolved in dry THF (10 ml) in a 25 ml round- bottomed flask, equipped with a magnetic rod and a septum. A solution of MeLi in Et₂0 (0.59 ml, 0.89 mmol, 1.5 M) was added rapidly to the solution cooled to - 78°C while stirring. The reaction mixture was stirred for 20 min. The reaction was stopped at -78°C by addition of H₂0 (3 ml). The aqueous phase was extracted with EtOAc (2 x 10 ml). The combined organic phases were washed with an aqueous solution of HCI (5%, 5 ml) and H₂0 (10 ml), dried, filtered and concentrated under reduced pressure. The residue was purified by flash column chromatography (20 x 1.5 cm, eluent: 20-40% Et₂0/hexane) to give the desired compound [56 mg, 95%, Rf = 0.52 (20% EtOAc/hexane), oil].

¹H-NMR (MeOD, 300MHz, δ): 7.45 (2 H, d, J= 8.42 Hz, H-Ar), 7.30 (2 H, d, J= 8.46 Hz, H-Ar), 6.32, 6.18 (2 H, AB, J= 11.1 Hz, H-6 y H-7), 6.12 (1 H, s, H-20), 5.26 (1 H, s broad, H-19_ε), 4.90 (1 H, s broad, H-19_z), 4.48 (1 H, m, H-1 ), 4.28 (1 H, m, H-3), 2.93 (1 H, m, H-14), 1.56 (6 H, s, 2 Me), 0.94 (9 H, s, t-BuSi), 0.93 (9 H, s, ---BuSi), 0.78 (3 H, s, Me-18), 0.14 (6 H, s, Me₂Si), 0.13 (3 H, s,

Me₂Si), 0.12 (3 H, s, Me₂Si). ¹³C-NMR (MeOD, 75.40 MHz, δ): 155.3 (C), 150.0 (C), 148.2 (C), 141.3 (C), 138.0 (C), 136.8 (C), 129.0 (CH), 125.4 (CH), 124.2 (CH), 119.6 (CH), 119.0 (CH), 112.0 (CH₂), 73.4 (C), 72.8 (CH), 68.9 (CH), 55.3 (CH), 47.2 (CH₂), 46.1 (CH₂), 38.0 (CH₂), 31.9 (2 CH₃), 30.0 (CH₂), 29.7 (CH₂), 26.5 (3 CH₃), 26.4 (3 CH₃), 24.5 (CH₂), 19.6 (CH₃), 19.1 (C), 19.0 (C), -4.2 (CH₃), -

4.4 (CH₃), -4.5 (CH₃), -4.7 (CH₃).

hU17E 1α-20-[4-(dimethylhvdroxymethvnphenyl]-17.20-didehvdro- 21.22.23.24.25.26.27-heptanor-vitamin D, (scheme 1. step 8^

The compound (42 mg, 0.064 mmol) was dissolved in dry THF (3 ml) in a 10 ml round-bottomed flask, equipped with a magnetic rod and a septum. A solution of TBAF in dry THF (573 μl, 0.636 mmol, 1.11 M) was added, via a syringe, to the solution. The reaction mixture was stirred at room temperature with light excluded for 26 h. The reaction was stopped by addition of a saturated solution of NH₄CI (3 ml). The aqueous phase was extracted with Et₂0 (2 x 5 ml). The combined organic phases were dried, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (15 x 1.5 cm, eluent: 50-100%

Et₂0/hexane), obtaining the desired vitamin [22.1 mg, 80%, Rf = 0.25 (80% EtOAc/hexane), white solid].

¹H-NMR (MeOD, 300MHz, δ): 7.45 (2 H, d, J= 8.3 Hz, H-Ar), 7.31 (2 H, d, J= 8.3 Hz, H-Ar), 6.39, 6.22 (2 H, AB, J= 11.1 Hz, H-6 y H-7), 6.13 (1 H, s, H-20),

5.35 (1 H, s broad, H-19_E), 4.96 (1 H, s broad, H-19_z), 4.41 (1 H, m, H-1 ), 4.17 (1 H, m, H-3), 1.56 (6 H, s, 2 Me), 0.80 (3 H, s, Me-18). ¹³C-NMR (MeOD, 75.40 MHz, δ): 155.4 (C), 149.8 (C), 148.2 (C), 141.8 (C), 138.1 (C), 136.3 (C), 129.0 (2 CH), 125.4 (2 CH), 124.7 (CH), 119.5 (CH), 118.9 (CH), 112.1 (CH₂), 72.8 (C), 71.5 (CH), 67.4 (CH), 55.4 (CH), 49.8 (C), 46.1 (CH₂), 43.7 (CH₂), 38.0

(CH₂), 31.8 (2 CH₃), 30.0 (CH₂), 26.7 (CH₂), 24.5 (2 CH₂), 19.4 (CH₃).

Example 2

a) Changing the E/Z ratio

The E/Z -ratio of the compound obtained in Example 1c) has an E/Z ratio of 4.4:1.

The ester obtained in Example 1^c) (E/Z 4.4:1), (100 mg, 0.24 mmol) was dissolved in dry THF (35 ml) in a 50 ml reaction tube with a side-branching tube and septum for the argon supply, equipped with a magnetic rod and a cold finger. 9- Fluorenone (10 mg, 0.06 mmol) was added to the solution. The reaction mixture was irradiated for 90 min and concentrated under reduced pressure. The residue was purified by rapid column chromatography (20 x 5 cm, eluent: 1 % Et₂0/hexane) to give the mixture [99 mg, 99%, E/Z (1 :4.2)].

¹H-NMR (CDCIs, 250 MHz, δ): 7.92 (2 H, d, J= 8.3 Hz, H-Ar), 7.23 (2 H, d,

J= 8 Hz, H-Ar), 6.2 (1 H, s, H-20), 4.07 (1 H, m, H-8), 3.9 (3 H, s, MeO), 2.72-2.29 (3 H, m, 2 H-16, H-14), 1.28 (3 H, s, Me-18), 0.90 (9 H, s, f-BuSi), 0.03 (3 H, s, Me₂Si), 0.02 (3 H, s, Me₂Si). ³C-NMR (CDCI3, 62.83 MHz, δ): 167.2 (C), 156.0 (C), 144.1 (C), 129.3 (CH), 128.7 (CH), 127.5 (C), 118.1 (CH), 69.7 (CH), 52.5 (CH), 51.9 (CH₃), 44.6 (C), 37.1 (CH₂), 34.2 (CH₂), 31.2 (CH₂), 25.8 (3 CH₃), 23.0 (CH₂), 20.5 (CH₃), 18.0 (C), 17.5 (CH₂), -4.8 (CH₃), -5.15 (CH₃).

b^ The so obtained product was converted according to the method of Example 1^d) to give the corresponding Z-isomer:

¹H-NMR (CDCI₃, 250 MHz, δ): 7.92 (2 H, d, J= 8.3 Hz, H-Ar), 7.22 (2 H, d,

J= 8.01 Hz, H-Ar), 6.21 (1 H, s, H-20), 4.12 (1 H, m, H-8), 3.88 (3 H, s, MeO), 2.68-2.38 (3 H, m, 2 H-16, H-14), 1.28 (3 H, s, Me-18). ¹³C-NMR (CDCI₃, 62.83 MHz, δ): 167.1 (C), 155.2 (C), 143.8 (C), 129.2 (CH), 128.7 (CH), 127.5 (C), 118.3 (CH), 69.3 (CH), 52.0 (CH), 51.9 (CH₃), 44.2 (C), 36.8 (CH₂), 33.4 (CH₂), 31.0 (CH₂), 22.4 (CH₂), 20.2 (CH₃), 17.2 (CH₂).

c) The obtained product was converted as described in Example 1^e) to give the corresponding Z-isomer:

¹H-NMR (CDCI₃, 250 MHz, δ): 7.96 (2 H, d, J= 8.3 Hz, H-Ar), 7.24 (2 H, d,

J= 8.14 Hz, H-Ar), 6.37 (1 H, s, H-20), 3.92 (3 H, s, MeO), 2.78-2.39 (3 H, m, H-14, 2 H-16), 0.98 (3 H, s, Me-18). ¹³C-NMR (CDCI₃, 62.83 MHz, δ): 211.2 (C), 167.0 (C), 152.8 (C), 143.3 (C), 129.1 (CH), 129.0 (CH), 128.1 (C), 120.2 (CH), 61.4 (CH), 52.1 (CH₃), 50.8 (C), 40.8 (CH₂), 35.3 (CH₂), 30.9 (CH₂), 23.5 (CH₂), 19.4 (CH₂), 19.36 (CH₃).

d. This product was further reacted as described in Example 1^f) to give the corresponding Z-isomer:

¹H-NMR (CD₂CI₂, 250 MHz, δ): 7.91 (2 H, d, J= 8.2 Hz, H-Ar), 7.25 (2 H, d,

J= 8.2 Hz, H-Ar), 6.35 (1 H, s, H-20), 6.24, 6.10 (2 H, AB, J= 1 1.2 Hz, H-6 y H-7), 5.22 (1 H, s broad, H-19_E), 4.88 (1 H, s broad, H-19₂), 4.40 (1 H, m, H-1 ), 4.19 (1 H, m, H-3), 3.87 (3 H, s, MeO), 0.90 (9 H, s, f-BuSi), 0.90 (3 H, s, Me-18), 0.88 (9 H, s, t-BuSi), 0.09 (6 H, s, Me₂Si), 0.06 (6 H, s, Me₂Si). ¹³C-NMR (CD₂CI₂, 62.83 MHz, δ): 167.6 (C=0), 156.3 (C), 149.2 (C), 144.8 (C), 140.7 (C), 136.6 (C), 130.0 (2 CH), 129.5 (2 CH), 128.5 (C), 123.6 (CH), 120.4 (CH), 119.5 (CH), 111.9 (CH₂), 72.7 (CH), 68.3 (CH), 57.1 (CH), 52.6 (CH₃), 48.1 (C), 46.7 (CH₂), 45.6 (CH₂), 37.5 (CH₂), 32.4 (CH₂), 29.4 (CH₂), 26.4 (6 CH₃), 23.9 (CH₂), 23.1 (CH₂), 19.1 (CH₃), 18.9 (C), 18.8 (C), -4.2 (CH₃), -4.2 (CH₃), -4.3 (CH₃), -4.5 (CH₃).

e) The so called Z-ester was converted into the corresponding 4-dimethylhydroxy- methyl substituted compound analogous to Example 1^g):

¹H-NMR (MeOD, 300MHz, δ): 7.41 (2 H, d, J= 8.22 Hz, H-Ar), 7.15 (2 H, d, J= 8.13 Hz, H-Ar), 6.35 (1 H, s, H-20), 6.28, 6.15 (2 H, AB, J= 1 1.1 Hz, H-6 y H-7), 5.26 (1 H, s broad, H-19_£), 4.89 (1 H, s broad, H-19_z), 4.49 (1 H, m, H-1 ), 4.28 (1 H, m, H-3), 2.74 (1 H, m, H-14), 1.56 (6 H, s, 2 Me), 0.95 (9 H, s, t-BuSi), 0.94 (3 H, s, Me-18), 0.93 (9 H, s, f-BuSi), 0.14 (6 H, s, Me₂Si), 0.12 (6 H, s,

Me₂Si). ³C-NMR (MeOD, 75.40 MHz, δ): 154.4 (C), 150.0 (C), 148.6 (C), 141.4 (C), 138.3 (C), 136.8 (C), 129.9 (CH), 124.8 (CH), 124.1 (CH), 121.7 (CH), 119.8 (CH), 111.9 (CH₂), 73.4 (CH), 72.8 (C), 69.0 (CH), 57.7 (CH), 47.2 (CH₂), 46.1 (CH₂), 38.1 (CH₂), 32.3 (CH₂), 31.9 (CH₃), 31.9 (CH₃), 29.7 (CH₂), 26.4 (3 CH₃), 26.4 (3 CH₃), 24.3 (CH₂), 23.6 (CH₂), 19.2 (CH₃), 19.1 (C), 19.0 (C), -4.3 (CH₃), -

4.5 (CH₃), -4.6 (CH₃), -4.8 (CH₃).

f Finally the protected vitamin D₃ analog so obtained was deprotected in the same manner as described in Example 1^h):

¹H-NMR (MeOD, 300MHz, δ): 7.44 (2 H, d, J= 8.26 Hz, H-Ar), 7.18 (2 H, d, J= 8.07 Hz, H-Ar), 6.38 (1 H, s, H-20), 6.37, 6.22 (2 H, AB, J= 11.2 Hz, H-6 y H-7), 5.39 (1 H, s broad, H-19_£), 4.99 (1 H, s broad, H-19₂), 4.44 (1 H, m, H-1), 4.20 (1 H, m, H-3), 2.88 (1 H, m, H-14), 1.60 (6 H, s, 2 Me), 0.98 (3 H, s, Me-18). ¹³C-NMR (MeOD, 75.40 MHz, δ): 154.4 (C), 149.8 (C), 148.6 (C), 141.8 (C), 138.3

(C), 136.2 (C), 129.9 (CH), 124.8 (CH), 124.7 (CH), 121.7 (CH), 119.7 (CH), 112.1 (CH₂), 72.9 (C), 71.4 (CH), 67.4 (CH), 57.7 (CH), 46.1 (CH₂), 43.7 (CH₂), 38.1 (CH₂), 32.3 (CH₂), 31.-9 (CH₃), 31.9 (CH₃), 29.8 (CH₂), 24.3 (CH₂), 23.5 (CH₂), 19.0 (CH₃).

Example 3

The product obtained after Example 1^c) was hydrogenated as follows:

A solution of the ester obtained in Example 1°) (125 mg, 0.30 mmol) was prepared in EtOH (5 ml) in a 10 ml round-bottomed flask, equipped with a magnetic rod and a septum. Pt0₂ (15 mg, 0.066 mmol) was then added. The mixture was stirred in an atmosphere of H₂ (normal pressure) for 1 h and then filtered through a No. 4 filter plate, washing the solids with Et₂0. The concentration under reduced pressure resulted in a residue which was purified by flash chromatography (7 x 1.5 cm, eluent: 5% Et₂0/hexane) to give the desired compound [120 mg, 96%, Rf

= 0.36 (3% Et2l/hexane), colourless oil].

¹H-NMR (CDCI₃, 250 MHz, d): 7.92 (2 H, d, J= 8.2 Hz, H-Ar), 7.22 (2 H, d, = 8.2 Hz, H-Ar), 4.02 (1 H, m, H-8), 3.89 (3 H, s, MeO), 2.73 (1 H, dd, J= 13.1 y 4.1 Hz, H-14), 0.96 (3 H, s, Me-18), 0.90 (9 H, s, t-BuSi), 0.02 (3 H, s, Me₂Si),

0.01 (3 H, s, Me₂Si). ¹³C-NMR (CDCI₃, 75.40 MHz, d): 167.1 (C=0), 148.3 (C), 129.4 (CH), 128.8 (CH), 127.5 (C), 69.1 (CH), 53.1 (CH), 52.4 (CH), 51.8 (CH₃), 41.8 (C), 38.6 (CH₂), 36.4 (CH₂), 34.6 (CH₂), 27.4 (CH₂), 25.8 (3 CH₃), 23.1 (CH₂), 18.0 (C), 17.5 (CH₂), 14.3 (CH₃), -4.8 (CH₃), -5.2 (CH₃).

The corresponding hydrogenated compound substituted in the meta-position of the phenyl ring with the methoxycarbonyl group was obtained in the same manner:

¹H-N R (CDCI₃, 250 MHz, d): 7.84 (2 H, m, H-Ar), 7.22 (2 H, m, H-Ar), 4.02

(1 H, m, H-8), 3.90 (3 H, s, MeO), 2.73 (1 H, dd, J= 13.3 y 3.8 Hz, H-14), 0.96 (3 H, s, Me-18), 0.90 (9 H, s, f-BuSi), 0.01 (3 H, s, Me₂Si), 0.00 (3 H, s, Me₂Si). ¹³C-NMR (CDCIg, 62.83 MHz, d): 167.3 (C=0), 142.8 (C), 133.4 (CH), 129.9 (C), 129.8 (CH), 128.0 (CH), 126.7 (CH), 69.1 (CH), 53.2 (CH), 52.4 (CH), 51.9 (CH₃), 41.8 (C), 38.5 (CH₂), 36.0 (CH₂), 34.6 (CH₂), 27.3 (CH₂), 25.8 (3 CH₃), 23.1 (CH₂), 18.0 (C), 17.5 (CH₂), 14.4 (CH₃), -4.85 (CH₃), -5.21 (CH₃).

Example 4

Introduction of a group R₃

t-BuLi (2.17mmol, 1.6 ml, 1.36M in pentane) was added dropwise over a solution of isomeric mixture (E/Z 1 :1 ) A (as indicated on the scheme on page 6; A was dried over P₂0₅ for 12 hours) (430 mg, 0.99 mmol) in THF (10 mi) at - 78°C. The pale yellow solution was stirred at -78°C for 45 minutes. Isobutylene oxide (285 mg, 3.95 mmol, 0.35 ml) and boron trifluoride diethyl etherate (560 mg, 3.95 mmol, 0.486 ml) was added via syringe and then allowed to reach -50°C in 1 hour.

The reaction was warmed to room temperature in an hour and quenched with water. The mixture was diluted with ether and washed with NaHC0₃ sat. and NaCI sat. The combined organic layers was dried, filtered and concentrated. Flash cromatography of the concentrate (2 x 25 cm, eluent 5-20% EtOAc-hexane) afforded the isomeric mixutre (E/Z: 1 :1 ) B (325 mg, 77%, Rf= 0.35 (20% EtOAc- hexane).

¹C-NMR: 7.26-7.02 (m, 8H, E/Z- Ar), 6.19 (s, 1 H, Z-C=CH), 6.00 (s, 1 H, E-C=CH), 4.13 (d, 1 H, J=2.4 Hz, H8E), 4.06 (d, 1 H, J= 2.25, H8Z), 2.76 (s, 2H, E-Ar-CH₂- C(CH₃)₂OH), 2.74 (s, 2H, E-Ar-CH₂-C(CH₃)₂OH), 1.24 (s, 12H, E/Z-C(CH₃)₂OH),

1.11 (s, 3H, Z-H18), 0.91 (s, 9H, E-OSiC(CH₃)₃), 0.9 (s,3H, E-H18), 0.89 (s, 9H, Z- OSiC(CH₃)₃), 0.047 (s, 6H, OSi(CH₃)₂), 0.024 (s, 3H, OSi(CH₃)₂), 0.009 (s, 3H, OSi(CH₃)₂).

The obtained mixture B (see the scheme on page 6) was converted further according to scheme 1 , step 4, treated with fluorenone, separated by column chromatography in E- and Z-isomers, and then reacted as indicated in steps 5 to 8 to give the following compounds: 1 ) A+B= CH,. R.,= OH: Z-configuration

¹C-NMR: 7.17 (1 H,t, J=7.4Hz, H-Ar), 7.04-7.00 (3H, m, H-Ar), 6.31 (1 H, d, J= 10.7 Hz, =CH-CH=), 6.31 (1 H, s, Ar-CH=), 6.0 (1 H, d, J= 10.7 Hz, =CH-CH=), 5.32

(1 H, s, =CH₂), 5.0 (1 H, s, =CH₂), 4.37 (1 H, m, CH-OH), 4.15 (1 H, m, CH-OH), 2.7 (2H, s, Ar-CH₂-C(CH₃)₂-OH), 1.16 (6H, s, -C(CH₃)₂-OH), 0.87 (3H, s, Me18).

¹³C-NMR: 153.72 (C), 148.40 (C), 142.33 (C), 139.20 (C), 137.60 (C), 134.40 (C), 131.70 (CH), 128.39 (CH), 127.63 (CH), 127.54 (CH), 124.71 (CH), 120.88 (CH),

118.24 (CH), 111.83 (CH₂), 71.05 (C), 71.02 (CH), 67.08 (CH), 56.73 (CH), 50.07 (CH₂), 47.64 (C), 45.63 (CH₂), 43.31 (CH₂), 37.16 (CH₂), 31.60 (CH₂), 29.44 (CH₃), 29.39 (CH₃), 29.19 (CH₂), 23.63 (CH₂), 22.79 (CH₂), 18.72 (CH₃).

2^ A+B= CH . R = OH: E-configuration

¹C-NMR: 7,23-7.17 (3H, m, H-Ar), 7.00 (1 H,t, J=6.1 Hz, H-Ar), 6.37 (1 H, d, J= 11.1 Hz, =CH-CH=), 6.10 (1 H, s, Ar-CH=), 6.10 (1 H, d, J= NO, =CH-CH=), 5.31 (1 H, s, =CH₂), 4.98 (1 H, s, =CH₂), 4.38 (1 H, m, CH-OH), 4.16 (1 H, m, CH-OH), 2.72 (2H, s, Ar-CH₂-C(CH₃)₂-OH), 1.19 (6H, s, -C(CH₃)₂-OH), 0.74 (3H, s, Me18).

¹³C-NMR: 155.36 (C), 148.39 (C), 142.22 (C), 138.76 (C), 138.24 (C), 134.50 (C), 130.82 (CH), 128.30 (CH), 128.25 (CH), 126.55 (CH) 124.69 (CH), 118.24 (CH), 118.09 (CH), 111.88 (CH₂), 71.02 (CH), 70.98 (C), 67.08 (CH), 54.32 (CH), 50.11 (CH₂), 48.77 (C), 45.63 (CH₂), 43.31 (CH₂), 37.08 (CH₂), 29.43 (CH₃), 29.37 (CH₃),

29.16 (CH₂), 23.78 (CH₂), 18.09 (CH₃).

In the same manner the E and Z isomers of the corresponding compound wherein R₃ is in het para-position have been prepared:

Z-configuration

C-NMR: 7.09 (4H, s, H-Ar), 6.32 (1 H, d, J= 11.6 Hz, =CH-CH=), 6.29 (1 H, s, Ar- CH=), 6.07 (1 H, d, J= 11.5 Hz, =CH-CH=), 5.30 (1 H, s, =CH₂), 5.0 (1 H, s, =CH₂), 4.38 (1 H, m, CH-OH), 4.15 (1H, m, CH-OH), 2.7 (2H, s, Ar-CH₂-C(CH₃)₂-OH), 1.16 (6H, s, -C(CH₃)₂-OH), 0.87 (3H, s, Me 18).

³C-N R: 153.68 (C), 148.41 (C), 142.37 (C), 137.40 (C), 136.00 (C), 134.39 (C), 129.94 (CH), 129.29 (CH), 124.73 (CH), 120.65 (CH), 118.23 (CH), 111.83 (CH₂), 71.04 (C), 70.94 (CH), 67.09 (CH), 56.76 (CH), 49.75 (CH₂), 47.60 (C), 45.64 (CH₂), 43.31 (CH₂),36.97 (CH₂), 31.69 (CH₂), 29.36 (CH₃), 29.32 (CH₃), 29.23 (CH₂), 23.70 (CH₂), 22.75 (CH₂), 18.71 (CH₃).

E-configuration

¹C-NMR: 7.26 (2H, d, J= 8.14 Hz, H-Ar), 7.14 (2H, d, J= 8.1 Hz, H-Ar), 6.37 (1 H, d, J= 11.4 Hz, =CH-CH=), 6.09 (1 H, d, J= 11.4Hz, =CH-CH=), 6.08 (1 H, s, Ar-CH=), 5.30 (1 H, s, =CH₂), 4.97 (1 H, s, =CH₂), 4.38 (1 H, m, CH-OH), 4.17 (1 H, m, CH- OH), 2.70 (2H, s, Ar-CH₂-C(CH₃)₂-OH), 1.16 (6H, s, -C(CH₃)₂-OH), 0.73 (3H, s, Me18).

¹³C-NMR: 154.95 (C), 148.41 (C), 142.29 (C), 137.14 (C), 135.90 (C), 134.44 (C), 130.71 (CH), 128.22 (CH), 124.73 (CH), 118.05 (CH), 1 17.93 (CH), 111.86 (CH₂), 71.06 (C), 71.00 (CH), 67.10 (CH), 54.37 (CH), 49.71 (CH₂), 48.77 (C), 45.66 (CH₂), 43.33 (CH₂), 37.04 (CH₂), 29.41 (CH₃), 29.35 (CH2), 29.19 (CH₂), 19.11 (CH₃).

Claims

An arocalciferol compound of the formula (I)

wherein:

- Ri is a hydrogen atom or a hydroxy group,

- A and B represent hydrogen or methyl, or together form the methylene group,

- R₂ is a group of the formula (II)

wherein R₃ is a group -(CH₂)_n-C(R₄)₂OH, wherein n has the value 0, 1 or 2, and R₄ is a straight, branched or cylcic alkyl group having 1-3 C-atoms, or the vinyl group, p is 1 (when the dotted line is a double bond) or 2.

2. A compound as claimed in claim 1 wherein R₃ is the meta- or para- dimethylhydroxymethyl group.

3. A compound as claimed in claim 1 wherein A+B represent the methylene group.

4. A compound as claimed in claim 1 wherein R., is hydroxy.

5. A compound as claimed in claim 1 wherein the dotted line represents a second bond.

6. A pharmaceutical composition comprising, in addition to pharmaceutically acceptable carrier and/or an auxilliary substance, at least one compound as claimed in claim 1 in an effective amount as the active ingredient.