Stereoselective Synthesis of Cholesteryl Derivatives Bearing a Chiral Allenic Group in the Side Chain
作者:Alain Burger、Charles Hetru、Bang Luu
DOI:10.1055/s-1989-27161
日期:——
Two cholesteryl allenic stereoisomers (aS)-11 and (aR)-11 are prepared stereoselectively. The key step of the synthesis is the coupling of pregnenolone to the lithium salt of the optically active 5-ethynyl-1,3-dioxolane (S)-8 or (R)-8. These two chiral synthons are obtained from the enantiomer primary alcohol (S)-3 and (R)-3, which are prepared according to a new synthetic pathway from methyl (2S)- and (2R)-2,3-O-isopropylideneglycerate [(S)-1 and (R)-1].
两种胆甾酯丙烯 stereoisomers (aS)-11 和 (aR)-11 被选择性地合成。合成的关键步骤是将孕甾酮与光学活性的5-炔基-1,3-二氧杂烯 (S)-8 或 (R)-8 的锂盐偶联。这两种手性合成单元是从对映体初级醇 (S)-3 和 (R)-3 中获得的,这两种醇是通过一种新的合成路径从甲基(2S)-和(2R)-2,3-O-异丙基乙烯基甘油酸盐 [(S)-1 和 (R)-1] 合成而成的。