化学
克莱森重排
烯丙基重排
脯氨酸
形式综合
立体化学
重排
有机化学
氨基酸
催化作用
生物化学
作者
Hongjun Jeon,Yundong Chung,Sanghee Kim
标识
DOI:10.1021/acs.joc.9b00933
摘要
A concise formal total synthesis of (−)-cephalotaxine was achieved via an ester enolate Claisen rearrangement (EECR). A series of EECRs of proline allyl esters were examined to obtain the desired relative stereochemistry of an azaspiranic tetracyclic backbone. An unexpected reversal or low diastereoselectivity of (Z)-cinnamyl ester was observed. The diastereoselectivity was controlled by substitution patterns of a styrene region. This result represents a useful guide in aiding the prediction of stereochemical outcome of EECR of α-amino allylic esters.
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