A Novel Two-Step Synthesis of Hexahydropyrazino[1,2-α]-quinolines
作者:Walter H. N. Nijhuis、Willem Verboom、David N. Reinhoudt
DOI:10.1055/s-1987-28033
日期:——
The hexahydropyrazino[1,2-a]quinolines 2 were prepared in good yields by reaction of 2-(4-substituted 1-piperazinyl)benzaldehydes 5 with malononitrile and subsequent thermal cyclization of the condensation products 6; the latter reaction takes place via a concerted [1,5] hydrogen transfer and subsequent ring closure by addition of a carbanion to the iminium double bond.