(2a), and 6-propoxy-4, 5-dihydro-2 (3H)-pyridone (2b) is described. Irradiation of 1 in tert- butyl alcohol solvent gave 2-methyl-2-propyl N-(ethoxycyclopropy1) carbamate (3). When the irradiation was conducted in tetrahydro-furan solvent, a precursor, ethoxycyclopropyl ...