The Synthesis of D-Heteroannulated 3β-Hydroxy-13α-androst-5-ene Derivatives via α-Oxoketene Dithioacetal and α-Oxohydroxymethylidene Synthons
摘要:
16-Ketene dithioacetal derivatives of 3 beta-hydroxy-13 alpha-androst-5-en-17-one react with amidine, benzamidine, or guanidine to yield novel pyrimido-fused D-heteroannulated steroids. The reactions of 3 beta-hydroxy-16-hydroxymethylidene-13 alpha-androst-5-en-17-one with N,N'-dinucleophiles furnish heterocycles containing a pyrazole ring fused to positions 16,17 of the sterane skeleton.
3 beta-Hydroxy-16,17-seco-13 alpha-androsta-5,16-dien-17-a1 was obtained from 3 beta-acetoxyandrost-5-en-17-one in six steps with a Grob fragmentation as the key step. This seco-steroid, containing a formyl group and an unsaturated side-chain in a sterically favourable cis position, is a useful synthon for the synthesis of novel heterocycles condensed to the 3 beta-hydroxy-13 alpha-androst-5-en-17-one skeleton.