Photochemical approach to naphthoxazoles and fused heterobenzoxazoles from 5-(phenyl/heteroarylethenyl)oxazoles

J Org Chem. 2011 Apr 15;76(8):2904-8. doi: 10.1021/jo1025942. Epub 2011 Mar 10.

Abstract

A new synthetic approach is presented for the synthesis of naphthoxazoles and fused heterobenzoxazoles. The starting 5-(aryl/furyl/thienyl/pyridyl ethenyl)oxazoles are prepared from the corresponding α,β-unsaturated aldehydes using Van Leusen reagent in very good yields and are transformed into naphthoxazoles and fused heterobenzoxazoles on irradiation under aerobic conditions and in the presence of iodine.