Hj. Tien et al., REDUCTION OF ACETYLSYDNONES WITH BOROHYDRIDE ANION - PREPARATION OF 4-(1-HYDROXYETHYL)SYDNONES, Journal of the Chinese Chemical Society, 42(6), 1995, pp. 987-989
Acetyl group on the sydnone ring can be reduced by using NaBH4 in MeOH
solution in good yields. Acetyl group on the sydnone ring is less rea
ctive for reduction than that on a phenyl ring when both rings are pre
sent.