论文部分内容阅读
Direct and sensitized photolyses ot 1-biphenylyl-2,2-dimethylcyclopropane gave 2-methyl-4-biphenylyl-1-butene as sole product.Comparison of the product formation quantum yields at zeroconversion in direct and sensitized photolyses(1,7×10~(-3)vs.1.8×10~(-3))indicated that the rearrangementtook place from the triplet excited state in both cases.A istepwise mechanism involving disrotatoryring opening of the cyclopropane and subsequent 1,3-H suprafacial shift is proposed and is consistentwith the reaction multiplicity result,the orbital and state correlation diagram analyses as well as theprediction based on the Large K and Small K Concept.
Direct and sensitized photolyses ot 1-biphenylyl-2,2-dimethylcyclopropane given 2-methyl-4-biphenylyl-1-butene as sole product. Comparison of the product formation quantum yield at zeroconversion in direct and sensitized photolyses (1,7 × 10 ~ (-3) vs.1.8 × 10 ~ (-3)) indicated that the rearrangementtook place from the triplet excited state in both cases. A istepwise mechanism involving disrotatoryring opening of the cyclopropane and subsequent1,3-H suprafacial shift is proposed and is consistentwith the reaction multiplicity result, the orbital and state correlation diagram analyzes as well as the prediction based on the Large K and Small K Concept.