J. Org. Chem. 1986,51, 2289-2297 by linear least-squares fitting of the data. Direct Photolysis of 3a. In 2 mL of degassed methylene chloride in a Pyrex tube was dissolved 1 mg of 3a. The contents of the tube were irradiated under a nitrogen atmosphere with the light from a 550-W, high-pressure, Hanovia mercury lamp, which was passed through a Pyrex filter. After 20 min 3a was completely decomposed. Analytical GLC showed that the only two products formed in >1% yield were 6a and 7a, which were present in a ratio of 3.3:l. Both products were shown to be stable to the reaction conditions. Sensitized Photolysis of 3a. A mixture of 0.5 mg of 3a and 15 mg benzophenone in 1 mL of degassed methylene chloride was irradiated as described above. Analytical GLC showed the major product (>98%) to be 6a. A small amount (
