Stereoselective Synthesis of Tabtoxinine-β-lactam by Using the Vinylogous Mukaiyama Aldol Reaction with Acetate-Type Vinylketene Silyl N,O-Acetal and α-Keto-β-lactam

Stereoselective total synthesis of tabtoxinine-β-lactam has been achieved. The vinylogous Mukaiyama aldol reaction with vinylketene silyl N,O-acetal and α-keto-β-lactam proceeded to afford the adduct possessing a TβL-skeleton with a tert-alcohol in high yield and stereoselectivity. Stereoselective introduction of the amino group has been accomplished by azidation at the α position of the imide followed by hydrogenolysis. A straightforward method to achieve the potent inhibitor of glutamine synthetase, possessing both α-hydroxy-β-lactam and α-amino acid moieties, has been established.