Carboxylic esters radical leaving groups: a new and efficient gas-phase synthesis of benzofurans
作者:Michael Black、J. I. G. Cadogan、Gary A. Cartwright、Hamish McNab、Andrew D. MacPherson
DOI:10.1039/c39930000959
日期:——
Flash vacuum pyrolysis (FVP) of o-allyloxycinnamate esters gives benzofurans in high yield, via cyclisation of a phenoxyl radical and subsequent cleavage of the carboxylic ester function; coumarins are obtained by FVP of the corresponding phenols.
catalytic cycle of the Pd/Al2O3 catalyzed redox isomerization of allyl alcohol. We show that the reactivity of allyl alcohol derived acrolein and enol can be involved in further cascade reactions leading to a diverse set of products. While the oxidation product acrolein can react via Michael and oxa-Michael reactions, the isomerization product enol can be readily involved in aldol condensation processes
Application of Baylis–Hillman Methodology in the Synthesis of Coumarin Derivatives
作者:Perry T. Kaye、M. A. Musa
DOI:10.1081/scc-120018937
日期:2003.1.6
Abstract A general, chemoselective approach to 3-substituted coumarins via Baylis–Hillman reactions of O-benzylated salicylaldehyde precursors has been demonstrated. Competitive cyclization to chromene derivatives is inhibited by conjugate addition of benzylamine or piperidine to the α,β-unsaturated ester intermediates.