Synthesis of “glycospirostanes”—Steroid sapogenins with a sugar-like ring F
摘要:
The synthesis of two "glycospirostanes" from 23-oxotigogenin acetate is described. (23S,24S,25R)-5 alpha-Spirostane-3 beta,23,24,25-tetraol was obtained by dehydrogenation followed by stereoselective reduction of the 23-oxo group and OSO4 dihydroxylation of the C24-C25 double bond. Allylic hydroxylation with SeO2 of 3 beta-acetoxy-5 alpha-spirost-23-ene obtained from 23-oxotigogenin acetate followed by OSO4 dihydroxylation of the C23-C24 double bond afforded (23R,24S,25R)-5 alpha-spirostane-3 beta,23,24,25-tetraol. (c) 2007 Elsevier Inc. All rights reserved.
Synthesis of “glycospirostanes”—Steroid sapogenins with a sugar-like ring F
摘要:
The synthesis of two "glycospirostanes" from 23-oxotigogenin acetate is described. (23S,24S,25R)-5 alpha-Spirostane-3 beta,23,24,25-tetraol was obtained by dehydrogenation followed by stereoselective reduction of the 23-oxo group and OSO4 dihydroxylation of the C24-C25 double bond. Allylic hydroxylation with SeO2 of 3 beta-acetoxy-5 alpha-spirost-23-ene obtained from 23-oxotigogenin acetate followed by OSO4 dihydroxylation of the C23-C24 double bond afforded (23R,24S,25R)-5 alpha-spirostane-3 beta,23,24,25-tetraol. (c) 2007 Elsevier Inc. All rights reserved.