Another interesting example included the use of ketone 181 for the preparation of the corresponding ribocyanohydrin 182a in 94% yield, which could be epimerized to form the thermodynamically more stable xylocyanohydrin 182b upon treatment with MeONa in MeOH in 89% yield (Scheme 32). 107 Subsequent mesylation of both stereoisomers 182a and 182b in pyridine led to the formation of sulfonates 183a and 183b, respectively, with yields of 80% and 71%. Further intramolecular cyclization of sulfonates 183a and 183b occurred upon treatment with DBU in MeCN, provideng sultones 184a and 184b with yields of 76% and 71%, respectively. Scheme 32. Synthesis of stereoisomeric 184a and 184b