Cleavage of ketone SAMP-hydrazones 1a-f with a saturated aqueous oxalic acid solution gives the corresponding ketones 2a-f in excellent yields and with high enantiomeric purity (ee = 90-99%). The chiral auxiliary SAMP is recovered from the aqueous phase in good yield (85%) and with unchanged enantiomeric purity. This racemisation free cleavage procedure is compatible with functionalities sensitive to oxidative cleavage conditions, such as ozonolysis, or to strong acids.
酮类SAMP-酰
肼1a-f与饱和
草酸水溶液反应,以优异的产率和高对映纯度(ee = 90-99%)得到相应的
酮类2a-f。手性辅助剂
SAMP从
水相中以良好产率(85%)和不变的对映纯度回收。这种无消旋化裂解过程与氧化裂解条件(如
臭氧分解)或强酸敏感的功能相容。