figshare
Browse
ol901679h_si_002.pdf (5.07 MB)

Asymmetric [3,3]- and [1,3]-Sigmatropic Rearrangements of γ-Allyloxy Vinylogous Urethanes

Download (5.07 MB)
journal contribution
posted on 2009-09-17, 00:00 authored by Yu-Jang Li, Yuan-Kang Chang, Guo-Ming Ho, Hua-Ming Huang
Vinylogous urethanes derived from condensation of prolinol or prolinol tert-butyldimethylsilyl ether with 4-allyloxyketoester were found to undergo a thermal [3,3]-sigmatropic rearrangement, providing compounds with N-substituted quaternary carbon centers. Cyclizations (subsequently or in situ) of the rearranged products generated hexahydro-3,4-dioxa-8a-aza-as-indacen-2-ones. Various terminally substituted allyloxy ketoesters and arylmethoxy ketoesters were found to generate tricyclic compounds via [1,3]-sigmatropic rearrangement. Finally, tricyclic lactones were transformed successfully into lactams.

History