摘要：

Evidence is given that during the course of the reduction of α,β-unsaturated ketones with lithium in liquid ammonia the β-carbon atom becomes nucleophilic and can be alkylated by a suitably placed electrophilic center. In the more usual case, the β-carbon becomes protonated by ammonia leading to an enolaie ion. Full details are given of the method briefly reported in a preliminary communication, by which trapping of that enolate ion with an alkyl halide or carbon dioxide leads to an alkylated or carboxylated saturated ketone in which the new group appears on the carbon which was the α-carbon of the original α,β-unsaturated system. The method has been used with six- as well as five-membered unsaturated ketones, with or without a hydrogen on the α-carbon. The free hydroxyl group of 4-methyltestosterone did not interfere with the reaction which led to 4,4-dimethyldihydrotestosterone.

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