Studies in polypropionate synthesis: high π-face selectivity in syn aldol reactions of tin(II) enolates from (R)- and (S)-1-benzyloxy-2-methylpentan-3-one.
作者:Ian Paterson、Richard D. Tillyer
DOI:10.1016/s0040-4039(00)74697-1
日期:1992.7
Use of Sn(OTf)2/Et3N in the aldol reactions of the α-chiral ethyl ketones (R)- or (S)-1 with aldehydes leads to high stereoselectivity (90–95% ds, >-97% ee) for the 1,2-syn-2,4-syn adduct 7 or ent-7. This substrate-based selectivity is rationalised by chelation of the Sn(II) enolate.
在α-手性乙基酮(R)-或(S)-1与醛的醛醇缩合反应中使用Sn(OTf)2 / Et 3 N会导致高立体选择性(90-95%ds,>-97%ee) )对于1,2- syn -2,4- syn syn加合物7或ent - 7。通过对Sn(II)烯醇盐进行螯合可以合理地实现这种基于底物的选择性。