ASYMMETRIC-SYNTHESIS OF ALPHA-SUBSTITUTED NITRILES AND CYANOHYDRINS BY OXIDATIVE CLEAVAGE OF CHIRAL ALDEHYDE HYDRAZONES WITH MAGNESIUM MONOPEROXYPHTHALATE

Optically active alpha- and alpha,beta-substituted aldehyde hydrazones 2, 4, and 7, which are readily available by asymmetric alkylation, Mi chael addition or [2,3]-Wittig rearrangement of chiral hydrazones can be transformed into nitriles 3 and 5 or cyanohydrins 8 by MMPP mediate d oxidation, respectively. This synthetic sequence offers a C-C connec tive entry into optically active functionalised nitriles with good ove rall yields (30 - 75 %) together with high diastereo- and enantioselec tivities (de = 76 - greater than or equal to 96 %, ee greater than or equal to 72 - greater than or equal to 97 %).