Phenoxathiins and (o-Hydroxyphenyl)phenyl sulfides from 1-Oxaspiro[2.5]octa-5,7-dien-4-ones

Abstract

A series of halogenated phenoxathiins (10a-c),(11a,b), and a 1-azaphenoxathiin (13) have been prepared satisfactorily by the reaction between l-oxaspiro[2.5]octa-5,7-dien-4-ones (6-spiroepoxy- 2,4-cyclohexadienones) (9a-c) and the appropriate halogenated thiophenolate anion. The method described provides a novel synthetic pathway to highly substituted phenoxathiins. Several (O-hydroxyphenyl)phenyl sulfides (14a-d) were also prepared with the anion of p-chlorothiophenol. Formation of the diphenyl sulfide (14b) with concomitant trapping of formaldehyde as a dimedone derivative (19) enabled a reaction pathway to be proposed.