摘要：

A test has been made of a stereochemical prediction for conjugate addition based on the intermediacy of d,π ∗-complexes in the reaction of organocopper reagents with α,β-enones. The chiral α,β-enone 7 has been synthesized and subjected to reaction with various methyl cuprate reagents. Under conditions favorable to lithium chelation to the α-alkoxycarbonyl system of 7, conjugate addition to 7 was found to proceed with high (13:1 to 33:1) 1,4-diastereoselectivity, the configuration of the major diastereomer being that predicted by the d,π ∗-complex model. A new and especially diastereoselective reagent has been generated by the reaction of LiCuMe 2 with 0.3 equivalent of water, a possible structure for which is presented.

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