Annelation reactions of 3-phenylthiobut-3-en-2-one. A new method of constructing fused phenols

Abstract

Reactions of 3-phenylthiobut-3-en-2-one with enolate anions of cyclohexanone and cyclopentanone gave good yields of 8a-hydroxy-3-phenylthio-2-decalone and 3a-hydroxy-6-phenylthiohexahydroindan-5-one which were readily converted into 5,6,7,8-tetrahydro-2-naphthol and indan-5-ol, respectively, on exposure to toluene-p-sulphonic acid: a similar reaction of the enolate of cycloheptanone and subsequent treatment with sodium ethoxide gave 2-hydroxy-5,6,7,8-tetrahydrobenzocycloheptene.