Novel synthesis of bifurans via furan-forming photocyclization of α-diketones conjugated with ene-yne
作者:Kazuhiko Nakatani、Kazuhito Tanabe、Isao Saito
DOI:10.1016/s0040-4039(97)00018-x
日期:1997.2
Upon photoirradiation at 366 nm alpha-diketones conjugated with ene-yne undergo cyclization to furan derivatives with the formation of carbene intermediates. In protic solvents the carbene was protonated to produce furan derivatives, whereas trapping the carbene in nonprotic solvents by adjacent carbonyl group led to the formation of a novel 2,2'-bifuran derivative in a quantitative yield. (C) 1997, Elsevier Science Ltd.
Tandem Cyclizations Involving Carbene as an Intermediate: Photochemical Reactions of Substituted 1,2-Diketones Conjugated with Ene-Yne
studying tandem cyclizations involving carbene. The photocyclization of 1,2-diketones conjugated with ene-yne to (2-furyl)carbene was employed as a carbene-generating system. Upon photoirradiation of 1,2-diketones possessing biphenyl and 2-acetyl-1-cyclopentenyl systems as a carbene trapping unit in aprotic solvents, we observed tandem cyclizations via a carbene intermediate to produce fluorenylfuran