Rongalite® promoted highly regioselective synthesis of β-hydroxy sulfides by ring opening of epoxides with disulfides

Rongaliteo (R) promotes cleavage of disulfides generating thiolate anions that then undergo facile ring opening of epoxides in the presence of K2CO3 to afford alpha-addition products 3 with good to excellent yields. The important features of this methodology are broad substrates scope, high yielding, reasonably rapid reaction rate, high regioselectivity and no requirement of metal catalysts. It should be noted that the thiolate anion attacks the epoxides derived from styrene to produce the corresponding alpha-addition products 3 with high regioselectivity, instead of the beta-addition regioisomer 4 that Could be formed from the attack of the nucleophile at the benzylic position. (C) 2009 Elsevier Ltd. All rights reserved.