Stereocontrolled transformation of cyclohexene b-amino esters into syn- or anti-difunctionalized acyclic b2,3-amino acid derivatives

A stereocontrolled approach to functionalized acyclic b2,3-amino acid derivatives was accomplished from cis- or trans-2-aminocyclohexenecarboxylates derived from bicyclic b-lactam regioisomers. The transformations were based on oxidative ring cleavage through the ring CeC double bond of the cyclohexene b-amino esters, followed by functionalization of the dialdehyde intermediates with different phosphoranes. This stereospecific and stereocontrolled procedure was applied to the synthesis of acylic b2,3-amino acid derivatives functionalized with ester, nitrile, keto, alkyl or arylalkyl groups