Synthesis of trihydroxy quinolizidine alkaloids: 1,3-addition reaction of allylmagnesium bromide to a sugar nitrone
作者:Dilip D Dhavale、Santosh M Jachak、Navnath P Karche、Claudio Trombini
DOI:10.1016/j.tet.2004.01.085
日期:2004.3
The synthesis of (1R,2R,3S,9aR) and (1R,2R,3S,9aS) trihydroxy quinolizidine alkaloids 3a and 3b from d-glucose derived nitrone 4 is described. The key transformation involves the 1,3-addition of allylmagnesium bromide to nitrone 4 that afforded high diastereoselectivity in the presence of TMSOTf. The N–O bond reductive cleavage, N-Cbz protection, ozonolysis, Wittig olefination, lactum formation and
描述了由d-葡萄糖衍生的硝酮4合成(1 R,2 R,3 S,9a R)和(1 R,2 R,3 S,9a S)三羟基喹oli嗪生物碱3a和3b。关键的转化涉及在TMSOTf存在下将烯丙基溴化镁1,3-加成至硝酮4,该硝酮具有很高的非对映选择性。N–O键的还原裂解,N -Cbz保护,臭氧分解,Wittig烯化,内酰胺形成和还原胺化级联反应提供了目标化合物3a和3b 总体产量高。