Sulfinimine-mediated reaction

The sulfinimine-mediated asymmetric Strecker reaction was developed by F.A. Davis et al. This method involves the addition of ethylaluminumcyanoisopropoxide to functionalized sulfinimines and the resulting diastereomeric a-amino nitriles are easily separated. Subsequent hydrolysis directly affords the enantiopure a-amino acids. This protocol was applied for the synthesis of polyoxamic acid lactone. ... 

Davis, F. A., Prasad, K. R., Carroll, P. J. Asymmetric Synthesis of Polyhydroxy a-Amino Acids with the Sulfinimine-Mediated Asymmetric Strecker Reaction 2-Amino 2-Deoxy L-Xylono-1,5-lactone (Polyoxamic Acid Lactone). J. Org. Chem. 2002, 67, 7802-7806. 

Substituted 2-oxazolidones 165 are useful chiral auxiliaries for diastereoselective functionalization at the a-carbon of their amide carbonyl group. The a-fluoroaldehydes 166 were prepared by a series of reactions electrophilic fluorination of the corresponding oxazolidinone sodium enolates with AMluorobenzenesulfonimine reductive removal of the auxiliary with LiBH4 and Dess-Martin oxidation. The aldehydes are so unstable for isolation that they are converted with (R)-/ -toluenesulfinamide to /7-toluenesul(inimines 167, which are isol-able and satisfactorily enantio-enriched. Chiral sulfinimine-mediated diastereoselective Strecker cyanation with aluminum cyanide provided cyanides 168 in excellent diastereose-lectivity, which were finally derived to 3-fluoroamino acids 169 (see Scheme 9.37) [63]. 

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