It was reasoned that the addition of sodium bromide or sodium iodide might facilitate the reaction. This proved to be the case as indicated by yields of the methyl ester 3 given in Table 1. Upon the addition of a catalytic amount (10 mol%) of sodium bromide, the reaction time decreased dramatically from 10 days to less than one day (Entry 1). Increasing the amount of sodium bromide to two equivalents resulted in the reaction being complete in 4 ...
