01481nas a2200145   4500008004100000245013800041210006900179260000800248300001400256490000900270520087900279100002601158700002101184856013001205       2017                        eng d00aIonic hydrogenation-directed stereoselective construction of C-20(H) stereogenic center in steroid side chains: Scope and limitations0 aIonic hydrogenationdirected stereoselective construction of C20H  cAPR  a2396-24140 v73  3 aStereoselective synthesis of steroidal C-20 tertiary alcohols with n-butyl, vinyl, furyl, thienyl, thiazolyl, aryl and pyridyl side chains via Grignard reaction or organolithium reagents have been realized starting from readily available 16-dehydropregnenolone acetate. The ionic hydrogenation of steroidal C-20 tertiary alcohols having furyl, methylfuryl, thienyl, phenyl and 4-methoxyphenyl side chains, resulted into the deoxygenated product with C-20 natural configuration in excellent yields. However, the alkyl, thiazolyl and pyridyl incorporated steroidal C-20 tertiary alcohols were failed under the same reaction condition. The scope of ionic hydrogenation is further highlighted through the stereoselective reduction of steroidal C-20,21-ene compounds with furyl, thienyl and 4-methoxyphenyl side chains gave the saturated compounds with C-20 natural configuration1 aShingate, Bapurao, B.1 aHazra, Braja, G.  uhttps://library.ncl.res.in/content/ionic-hydrogenation-directed-stereoselective-construction-c-20h-stereogenic-center-steroid