Stereoselective aldol condensations via alkenyloxy dialkoxyboranes: synthetic applications using thioesters
作者:Cesare Gennari、Anna Bernardi、Silvia Cardani、Carlo Scolastico
DOI:10.1016/0040-4020(84)85086-3
日期:1984.1
dialkoxyboranes derived from thioesters were found to be stereoconvergent: both Z and E enolates give syn aldol condensation products. The thioester additions to chiral aldehydes were studied. Internal selectivity (syn) was usually very high, while the relative stereoselectivity ranged from poor to good, depending on the specific aldehyde used. The aldol products were transformed to known compounds for correlation
进行了详细的研究,将硫代丙酸苯基酯与亚乙基氯硼酸酯(ECB)和二异丙基乙胺(DPEA)进行烯醇化,随后对这些烯醇化物进行醇醛缩合反应。已发现衍生自硫酯的烯氧基二烷氧基硼烷是立体收敛的:Z和E的烯醇盐均生成顺式醇醛缩合产物。研究了手性醛中硫代酯的添加。内部选择性(syn)通常很高,而相对的立体选择性则根据所使用的特定醛的不同,从差到好。将醛醇缩合产物转化为已知化合物以进行相关。