Competitive intramolecular aminolysis: Relative rates of 5-and 6-membered lactam ring closure

Article abstract of DOI:10.1016/S0040-4039(00)76532-4

Methyl 4,5-diaminopentanoate (4,5-Dape Me) undergoes competitive intramolecular aminolysis to 5-aminomethyl-2-pyrrolidinone (L5) and 5-amino-2-piperidinone (L6) in dilute alkaline aqueous solution at 25°C. Use of this single compound provides an ideal case for assessing the relative rates of 5- and 6-membered lactam ring closure. Assessments are also made using the intramolecular aminolysis of pairs of compounds: methyl 2,4-diaminobutanoate (2,4-Dab Me) and methyl 2,5-diaminopentanoate (2,5-Dape Me); methyl 4-aminobutanoate (4-Ab Me) and methyl 5-aminopentanoate (5-Ape Me).