α-Bromo ketones, -esters and -nitriles react with chromium dichloride and ketones in a Barbier-type reaction to yield the kinetic crossed aldol products with one or two new quarternary centers. The reaction does not require special activation of the reagent, proceeds at room temperature and is suitable for microscale preparations. Crotonates react highly regioselective to yield α-products. The influence of solvents is discussed.
δ-
溴酮、-酯和-
硝基化合物与二
氯化
铬和酮发生巴比耶型反应,生成具有一个或两个新的四元中心的动力学交叉醛醇产物。该反应不需要对试剂进行特殊活化,在室温下进行,适合微量制备。
巴豆酸盐反应具有高度的区域选择性,可生成 δ 产物。讨论了溶剂的影响。