M. Black et al., CARBOXYLIC ESTERS AS RADICAL LEAVING GROUPS - A NEW AND EFFICIENT GAS-PHASE SYNTHESIS OF BENZOFURANS, Journal of the Chemical Society, Chemical Communications, (11), 1993, pp. 959-960
Flash vacuum pyrolysis (FVP) of o-allyloxycinnamate esters gives benzo
furans in high yield, via cyclisation of a phenoxyl radical and subseq
uent cleavage of the carboxylic ester function; coumarins are obtained
by FVP of the corresponding phenols.