Cyclisation of Ortho -Cyclohexenyl Phenols via Epoxidation^#

This paper is dedicated to Professor B.S. Thyagarajan of the University of Texas at San Antanio, U.S.A. on the occasion of his 65th birth anniversary.

Abstract

A number of ortho -cyclohexenyl phenols 2(a–i) have been cyclised by treatment with one equivalent of m-chloroper-oxybenzoic acid in refluxing benzene for 4 h to furnish linearly fused 1-hydroxy-1,2,3,4,4a,9a-hexahydrodibenzofurans 3(a–i) (70–80%) and bicyclic 3-hydroxy-1,3-ethanochromans 4(a–f) (10–20%). Products 3(a–i) were oxidised with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (excess) in refluxing dry xylene for 6 h to give 2,3-dihydrodibenzofuran-1 (2H)-ones 6(a–i) (85–95%).

This paper is dedicated to Professor B.S. Thyagarajan of the University of Texas at San Antanio, U.S.A. on the occasion of his 65th birth anniversary.

Notes

This paper is dedicated to Professor B.S. Thyagarajan of the University of Texas at San Antanio, U.S.A. on the occasion of his 65th birth anniversary.