G. Capozzi et al., ALPHA-OXOSULFINES - NEW-GENERATION METHODS AND REACTIVITY, Phosphorus, sulfur and silicon and the related elements, 120, 1997, pp. 317-318
alpha-oxothiophthalimides 2 can be oxidised the corresponding sulfinim
ides 3 with m-chloroperoxybenzoic acid. Derivatives 3 in the presence
of catalytic amount of pyridine generate the alpha-oxosulfines 4 which
can be trapped by diene 5 to give dihydrothiopyranes 6 as mixture of
diastereoisomers. The method appears simple and general since alkyl, a
ryl and hetroaryl substituted thiopthtalimides can be fruitfully used.