N. Yamazaki et al., STEREOSPECIFIC REDOX REACTION DIRECTED BY A SULFINYL GROUP, Phosphorus, sulfur and silicon and the related elements, 120, 1997, pp. 445-446
Stereochemistry of reductions of a pyridinium and quinoliniums with an
asymmetric sulfinyl group has been studied. Dithionite and borohydrid
e prefer the face characterized by a lone pair on sulfur atom. Dihydro
pyridine prefers the face characterized by a S-O bond.