Solution kinetics of CC-1065 A-ring opening: Substituent effects and general acid/base catalysis

A comprehensive pH-rate study is undertaken using spectral global fitting and chloride nucleophile trapping of CC-1065's A-ring bearing the 2-substituents, and spectral global fitting is developed to study intermediates in complex photochemical reactions. The results imply that the general-acid-catalyzed alkylation of DNA minor groove by the A-ring is possible, but the 2-substituent does not affect the pKa of the protonated carbonyl of the A-ring and has little effect on the rate of nucleophile trapping.