Alkylation of the aza-enolate of valerolactim methyl ether with electrophiles affords a-alkyl lactims that may be hydrolysed under mild acidic conditions to afford their corresponding alpha-alkyl-8-amino esters as their hydrochloride salts. Neutralisation of these salts with base results in smooth intramolecular cyclisation to afford their corresponding alpha-alkyl lactams in excellent yield.
Taylor, P. J. M., Bull, S. D., & Andrews, P. C. (2006). An aza-enolate alkylation strategy for the synthesis of alpha-alkyl-delta-amino esters and alpha-alkyl valerolactams. Synlett, (9), 1347-1350. https://doi.org/10.1055/s-2006-939726