The Preparation of Enantiomerically Pure 3,4-Epoxy-1-butene and 3-Butene-1,2-diol

Single enantiomer 2-hydroxy-3-butenyl tosylate is a key precursor for single enantiomer 3,4-epoxy-1-butene and 3-butene-1,2-diol. The epoxide results from ring-closure of the hydroxy-­tosylate while the diol is obtained through the intermediacy of the corresponding cyclic carbonate. This latter sequence avoids the loss of enantiomeric purity observed through direct hydrolysis.