我们描述了一种新的串联自由基环化策略,用于构建天然四喹烷 crinipellin A 的拥挤角三喹烷部分。 详细介绍了三个 5,5-二取代-1,4-二甲基-1,3-环戊二烯的制备和环化. 这种环化策略导致环戊二烯核的 1,4-官能化,由烯丙基环化介导。每次串联环化以 5:1 的比例产生两种非对映体三喹烷。次要的非对映异构体对 crinipellin A 的 D 环异丙基具有正确的相对立体化学。还描述了与自由基环化平行的串联阳离子环化
Dimethylaluminum methaneselenolate—a useful reagent for the preparation of selenoesters. A new friedel-crafts acylation procedure promoted by Cu(I)
作者:Alan P. Kozikowski、Anthony Ames
DOI:10.1016/s0040-4020(01)96721-3
日期:1985.1
The preparation of a new aluminum reagent, dmiethylaluminum methaneselenolate (Me2AlSeMe) is described. The reactivity of this aluminum reagent toward a variety of organic substrates has been studied. Me2AlSeMe will convert O-alkyl esters to selenoesters in high yield. These selenoesters function as extremely reactive acyl transfer agents and are converted to acids, esters, and amides on reaction with