A Synthesis of Progesterone from Ergosterol¹

A New Look at the Most Successful Prodrugs for Active Vitamin D (D Hormone): Alfacalcidol and Doxercalciferol

“…The ten-step synthetic route to doxercalciferol ( 21 ) starting from ergosterol ( 23 ) is well documented in the literature by DeLuca [ 34 ]. Thus, Oppenauer oxidation of ergosterol ( 23 ) gave 4,7,22-triene-3-one 24 in 77% yield, which was followed by acid catalyzed double bond conjugation according to the procedure outlined by Shepherd [ 35 ]. This sequence afforded 4,6,22-triene-3-one 25 in 80% yield.…”

The conversion of lanosterol, cycloartenol and 24-methylenecycloartanol into poriferasterol by Ochromonas malhamensis

“…Table 1. To check that the 3H was not randomized during the incubation period, theporiferasterol from each incubation, after crystallization, was oxidized by the Oppenauer reaction (Shepherd et al 1955) and the resulting poriferastenone refluxed in methanolic KOH. In all cases the reisolated and purified poriferastenone was completely devoid of 3H, showing that no randomization of label had occurred.…”

Short-step Synthesis of Chenodiol from Stigmasterol

“…9,10) The side chain of compound 8 was selectively ozonolyzed to afford an aldehyde, 11) this then being subjected to the Wittig reaction. 12) Preparatory to oxidation of the C-7 position, resulting enone 9 was treated with chloranil to efficiently give dienone 10.…”

“…Mp 154-156 C. ½ (6,7,22E)-6,7-Epoxy-3-oxo-4,22-choladien-24-oic acid ethyl ester (11). Method A: To a refluxed solution of 10 (200 mg, 0.504 mmol) and BHT (11.1 mg) in CHCl 3 (15 ml) was added three portions of mCPBA (80%, 82 mg  3, 0.38 mmol  3) at 2-h intervals.…”