Acylnitrene route to vicinal amino alcohols. Application to the synthesis of (-)-bestatin and analogues

The synthesis of (-)-bestatin and its analogues has been undertaken through a new method. Bestatin and its analogues are naturally occurring small peptides with a nonproteinogenic alpha-hydroxy-beta-amino acid at the N-terminus of the peptide chain. The novel technique uses an intramolecular acylnitrene-mediated aziridination to produce a key bicyclic aziridine in excellent yield and stereoselectivity. The aziridine can be opened by using organometallic reagents to produce a series of substituted oxazolidinones. The latter compounds can be easily transformed to bestatin and its analogues.