Intramolecular α-acylamino radical cyclizations with acylsilanes in the preparation of polyhydroxylated alkaloids: (+)-lentiginosine, (+)-1,8a-di-epi-lentiginosine, and (+)-1,2-di-epi-swainsonine
作者:Ming-Jen Chen、Yeun-Min Tsai
DOI:10.1016/j.tetlet.2007.07.021
日期:2007.9
Acylsilanes with latent α-acylamino radical functionality were prepared from different chiral templates. Radical cyclizations of these acylsilanes efficiently constructed polyhydroxylated indolizidine derivatives with excellent stereoselectivity at the bridgehead position. These cyclization products were converted to (+)-lentiginosine, (+)-1,8a-di-epi-lentiginosine, and (+)-1,2-di-epi-swainsonine.
从不同的手性模板制备具有潜在的α-酰基氨基自由基官能团的酰基硅烷。这些酰基硅烷的自由基环化有效地构建了在桥头位置具有出色立体选择性的多羟基化吲哚并咪唑衍生物。这些环化产物被转化为(+)-龙胆草碱,(+)-1,8a-二-表-龙胆草碱和(+)-1,2-二表-swainsonine。