Asymmetric synthesis of 4-amino-γ-butyrolactones via lithium amide conjugate addition

The conjugate addition of homochiral lithium N-benzyl-N-(α-methylbenzyl)amide to a range of γ-tert-butyldimethylsilyloxy but-2-enoates and but-2-enamides, and subsequent enolate functionalisation followed by deprotection, allows access to a range of 3-substituted-4-amino-γ-butyrolactones.