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Issue 0, 1985
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Unsaturated steroids. Part 12. Synthesis of 1α,3β-dihydroxy-24-nor-9,10-secochola-5,7,10(19)trien-23-oic (calcitroic) acid and of the cholic-and 25-homocholic acid analogues

Abstract

The three title compounds have been synthesized by the same general method. Thus, methyl 3β-hydroxy-24-nor-5α-chol-7-en-23-oate (3; R = CO2Me), derived from 3β-acetoxypregn-7-ene-22-carbaldehyde (2), gave methyl 3-oxo-24-nor-5α-chol-7-en-23-oate (4; R = H,R′= CH3). Bromination of this to the 2ξ,4ξ-dibromo derivative (4; R = Br, R′= Me) followed by dehydrobromination formed the corresponding 1,4,7-triene-3-one (5). The corresponding enol acetate (6) was reduced to the 1,5,7-triene (7) which was converted into the adduct (8; R = H) with 4-phenyl-1,2,4-triazoline-3,5-dione; the 3β-dimethyl-t-butylsilyl ether of (8;R = H)gave the 1α,2α-epoxide(9; R = Me2ButSi). Removal of the silyl ether group with acid, and then of the triazoline residue with pyridine–1,5-diazabicyclo[4.3.0] non-5-ene gave methyl 3β-hydroxy-1α,2α-epoxy-24-norchola-5,7-dien-23-oate (10; R = Me). Reduction of the corresponding acid (10; R = H) gave 1α,3β-dihydroxy-24-norchola-5,7-dien-23-oic acid (11; R = H). Photolysis/thermolysis of the corresponding methyl ester (11; R = Me) followed by saponification gave 1α,3β-dihydroxy-24-nor-9,10-secochola-5,7,10(19)trien-23-oic acid (calcitroic acid)(1; R = H, n= 1). The analogous cholic (1; R = H, n= 2) and 25-homocholic acid (1; R = H, n= 3) derivatives were similarly synthesized.

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Article information


J. Chem. Soc., Perkin Trans. 1, 1985, 1331-1336
Article type
Paper

Unsaturated steroids. Part 12. Synthesis of 1α,3β-dihydroxy-24-nor-9,10-secochola-5,7,10(19)trien-23-oic (calcitroic) acid and of the cholic-and 25-homocholic acid analogues

B. R. de Costa, N. Makk, J. M. Midgley, N. T. Modi, R. A. Watt and W. B. Whalley, J. Chem. Soc., Perkin Trans. 1, 1985, 1331
DOI: 10.1039/P19850001331

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