Parker Kathlyn A, Xie Qiuzhe
Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794, USA.
Org Lett. 2008 Apr 3;10(7):1349-52. doi: 10.1021/ol702989g. Epub 2008 Mar 4.
A short sequence based on asymmetric catalysis, chirality transfer, and an optimized carbometallation protocol gave an anti,anti stereotriad building block in six steps. Both enantiomers of the chirality source, N-methyl ephedrine, are inexpensive, and the auxiliary is recoverable. In one chiral series, the building block was converted to the "B-2" intermediate in Miyashita's synthesis of scytophycin C; in the enantiomeric series, it was converted to a key intermediate for aplyronine A and to the polyketide "cap" for the callipeltins.
基于不对称催化、手性转移和优化的碳金属化方案的短序列，经过六步反应得到了一个反式、反式立体三联体构建单元。手性源N-甲基麻黄碱的两种对映体都价格低廉，且助剂可回收。在一个手性系列中，该构建单元在宫下合成多球霉素C的过程中转化为“B-2”中间体；在对映体系列中，它转化为海兔毒素A的关键中间体和Callipeltins的聚酮“帽”。
