Regioselective C5-alkylation and C5-methylcarbamate formation of 2,3-dihydro-4-pyridones and C3-alkylation and C3-methylcarbamate formation of 4-(pyrrolidin-1-yl)furan-2(5H)-one

Reactions of N-alkyl-2,3-dihydro-4-pyridones and 4-(pyrrolidin-1-yl)furan-2(5H)-one with aldehydes and triethylsilane in a one-flask procedure provided C5 and C3 alkylated derivatives, respectively. Mannich-type reactions with formaldehyde and carbamates in the presence of lithium perchlorate furnished C5/C3 methylcarbamates