Furan ring opening-isochromene ring closure:a new approach to isochromene ring synthesis

摘要

A new approach toward the synthesis of 1H-isochromenes based on the recyclization of the furan ring in the corresponding ortho-hydroxymethylbenzylfurans is described.The isochromene framework is a frequent structural motif in naturally occurring molecules.For example,flaccidin isolated from the orchids Dendrobium amoenum and Coelogyne flaccida includes an isochromene framework.