New syntheses of 19,21-dihydroxypregn-4-ene-3,20-dione, 21-hydroxy-19-norpregn-4-ene-3,20-dione, and 11β,19,21-trihydroxypregn-4-ene-3,20-dione
- 1 January 1983
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 1
- No. 12,p. 2945-2951
- https://doi.org/10.1039/p19830002945
Abstract
19,21-Dihydroxypregn-4-ene-3,20-dione has been synthesized from 3β-acetoxypregn-5-en-20-one via the ‘hypoiodite reaction’[treatment of the 5α-bromo-6β-hydroxy derivative with Pb(OAc)4 and I2, with irradiation], and Henbest acetoxylation at C-21; oxidation of the intermediate 21-monoacetate to the 19-oxo derivative and alkaline cleavage gave 21-hydroxy-19-norpregn-4-ene-3,20-dione. A similar synthesis of 11β,19,21-trihydroxypreg-4-ene-3,20-dione from 3β-acetoxypregn-5-ene-11,20-dione proceeded through intermediates with the 11β-hydroxy function protected as its acetate. Unusual features mainly of conformational origin were observed in the presence of the 11β-acetoxy substituent; some were helpful to the synthesis, while others led to undesirable side reactions.This publication has 0 references indexed in Scilit: