Efficient photochemical transformation of spiro[4.n]-2,5-diones to γ-alkylidene γ-butyrolactones: its relevance to photostability of Fredericamycin A
Abstract
Irradiation of a variety of model spirodiones related to the antitumour antibiotic Fredericamycin A in various solvents at 300 nm furnishes quantitative yields of γ-alkylidene γ-butyrolactones; its relevance to the typical shape alteration, photostability and consequent biological response of Fredericamycin is discussed.