Polysubstituted Piperidines via Iodolactonization: Application to the Asymmetric Synthesis of (+)-Pseudodistomin D
作者:Stephen G. Davies、Ai M. Fletcher、James A. Lee、Paul M. Roberts、Angela J. Russell、Rachael J. Taylor、Anthony D. Thomson、James E. Thomson
DOI:10.1021/ol300209s
日期:2012.4.6
Conjugate addition of lithium (S)-N-allyl-N-(alpha-methyl-p-methoxybenzyl)amide to methyl (E,E)-hepta-2,5-dienoate furnished the corresponding beta-amino ester. N-Protecting group manipulation, ring-closing metathesis, and ester hydrolysis gave enantiopure [N(1')-tert-butoxycarbonyl-1,2,3,6-tetrahydropyridin-2'-yl]ethanoic acid. Subsequent iodolactonization gave a bicyclic iodolactone scaffold. This key intermediate was elaborated to (+)-pseudodistomin D [in >99% ee and 7% yield over 16 steps from methyl (E,E)-hepta-2,5-dienoate].