N-Alkylation and [2,3]-sigmatropic rearrangement of N-allyl α-amino esters

N-Alkylation of N-allyl α-amino esters and [2,3]-Stevens rearrangement occur in one pot on warming in the solvent DMF, with the bases K2CO3 and DBU; this in situ formation of the quaternary ammonium salts and rearrangement of the subsequent ylides gives N,N-dialkylated allyl glycine derivatives.