01433nas a2200265   4500008004100000022001400041245011900055210006900174260010600243300001400349490000700363520042300370653000600793653001500799653002400814653002500838653003000863653002900893100002600922700002100948700002200969700002400991700002501015856012701040       2006                        eng d  a0040-403900aStereoselective syntheses of unnatural steroidal C(20R) aldehydes by ionic hydrogenation of C-20 tertiary alcohols0 aStereoselective syntheses of unnatural steroidal C20R aldehydes   aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcDEC  a9343-93470 v473 a<p>Syntheses of three unnatural steroidal C(20R) aldehydes have been realised from 16-dehydropregnenol one acetate. The salient feature of the synthesis is the ionic hydrogenation of C-20 tertiary alcohols leading to the formation of the C(20R) unnatural isomer with complete stereoselectivity. Oxidative hydrolysis of the dithiane moiety furnished the C(20R) aldehydes. (c) 2006 Elsevier Ltd. All rights reserved.</p>10a110a3-dithiane10aionic hydrogenation10aoxidative hydrolysis10astereoselective synthesis10aunnatural C-20 aldehydes1 aShingate, Bapurao, B.1 aHazra, Braja, G.1 aPore, Vandana, S.1 aGonnade, Rajesh, G.1 aBhadbhade, Mohan, M.  uhttps://library.ncl.res.in/content/stereoselective-syntheses-unnatural-steroidal-c20r-aldehydes-ionic-hydrogenation-c-20-0