作者:Michael E. Jung、Alexandra van den Heuvel
DOI:10.1021/ol0358760
日期:2003.11.1
process is described in which a secondary epoxy silyl ether is converted into the 1,5-bis-silyloxy-3-alkanone in good yield. Thus, treatment of the epoxy silyl ether 8 with TBSOTf and base affords the silyl enol ether 9 via non-aldol aldol rearrangement and addition of benzaldehyde and TBSOTf gives the ketone 10 with 4:1 syn selectivity. The diastereoselectivity changes to an anti preference for most aldehydes
[反应:见正文]描述了一种新的单锅串联醛醇缩合工艺,其中将仲环氧甲硅烷基醚以良好的收率转化为1,5-双-甲硅烷基氧基-3-烷酮。因此,用TBSOTf和碱处理环氧甲硅烷基醚8通过非醛醇缩醛重排得到甲硅烷基烯醇醚9,并且苯甲醛和TBSOTf的添加产生具有4:1顺式选择性的酮10。非对映选择性改变成对大多数醛的反偏好。这种反选择性压倒了正常的Felkin-Ahn偏好;即,即使是抗Felkin-Ahn,1,5-抗异构体也占主导地位。