N. Mase et al., Diastereoselective radical hydrogenation of alpha-(1-hydroxyalkyl)vinyl sulfoxides and sulfones controlled by intramolecular hydrogen bonding, J ORG CHEM, 65(21), 2000, pp. 7083-7090
The reaction of (S)-alpha-(1-hydroxyallryl)vinyl sulfoxides (S)-5 with alky
l radicals and, tributyltin hydride gave the addition-hydrogenation product
s with high diastereoselectivity, whereas the reaction with (R)-alpha-(1-hy
droxyalkyl)vinyl sulfoxides (R)-5 resulted in complete recovery of the star
ting sulfoxides. Stereoselective intramolecular hydrogen bonding between th
e hydroxy group and the diastereotopic sulfonyl oxygen led to high diastere
oselectivity in the radical reaction of alpha-(1-hydroxyethyl)vinyl sulfone
12. An important role of intramolecular hydrogen bonding on the diastereos
electivity as well as the reactivity toward alkyl radicals is discussed.