1,3-Dienes can be converted to N-p-toluenesulfonylpyrroles in two step
s: 1) [4+2]-cycloaddition with N-sulfinyl-p-toluenesulfonamide and 2)
conversion of the 3,6-dihydro-1,2-thiazine oxide adduct to a pyrrole u
sing triethylamine-trimethylphosphite.