Unusual heterocyclisation in the transformation of 6-halomethylsulfonyl-substituted bicyclo[3.1.1]heptane under Ramberg-Backlund reaction conditions

Abstract

Boiling of exo-6-bromo-syn-7-bromo(chloro)methylsulfonyl-endo-6-phenylbicyclo[3.1.1]heptane in water-dioxane solutions of NaOH results in anti-6-hydroxy-7-methylene-syn-6-phenylbicyclo[3.1.1]heptane according to the Ramberg-Backlund reaction; in addition, a product of unusual heterocyclisation is formed, namely, 3-oxa-2-phenyl-5-thiatricyclo[4.4.0.0^2,7]decane S,S-dioxide.