A new course of the Perkin cyclization of 2-(2-formyl-6-methoxyphenoxy)-alkanoic acids. Synthesis of 2-alkyl-7-methoxy-5-nitrobenzobfurans

摘要

2-Alkyl-7-methoxy-5-nitrobenzobfuran,2-alkyl-9-methoxy-7-nitro-3-oxo-2,3-dihydro-5H-benzoe1,4-dioxepin-5-yl acetate and 2-alkyl-5-hydroxy-9-methoxy-7-nitro-5H-benzoe1,4-dioxepin-3-one were formed as a result of the cyclization of 2-(2-formyl-6-methoxy-4-nitrophenoxy)alkanoic acids under classical Perkin reaction conditions. The products were characterized by spectroscopic methods and the mechanism of the cyclization is discussed. (C) 2008 Elsevier Ltd. All rights reserved.