Efficient synthetic methodology for 1,3-dithiolane 1 -oxides via singlet oxidation of 1,3-dithiolanest

Singlet oxidation of 1,3-dithiolanes furnishes synthetically useful yields of 1,3-dithiolane 1-oxides. However, 2-ethyl-2-phenyl-1,3-dithiolane13 gave 2-ethyl-4-hydroxy-2-phenyl-1,3-dithiolane 19 as a major product.