Efficient synthesis of 5,8-disubstituted-1,4-dihydrobenzoxathiin-3-oxides and their isomeric structures, 4,7-disubstituted-1,3-dihydrobenzo[b] thiophene-2,2-dioxides

Abstract Functionalized dihydrobenzoxathiin oxides and dihydrobenzothiophene-2,2-dioxides 11 – 18 have been prepared via trapping of sulfur dioxide under photolytic or ground state conditions.