propargyl bromide, the preparation of 2-methylene-5-trimethylsilyl-pent-4-yn-1-ol was improved. This latter is the precursor of the corresponding aldehyde which was used for the first time as a dienophile in [4+2] reactions. The cycloadducts were obtained in very high yields and in a totally diastereoselective manner.
通过分别使用一当量的炔丙基醇
锌和甲
硅烷基化的炔丙基
溴,改进了2-亚甲基-5-三甲基甲
硅烷基-戊-4-yn-1-醇的制备。后者是相应醛的前体,其在[4 + 2]反应中首次用作亲二烯体。以非常高的产率和完全非对映选择性的方式获得环加合物。