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试剂和合成基元由于合成工作日益活跃,因此对于可以构成特殊结构单元的并可以多方面应用的合成试剂与合成基元的需求也自然增大了。这里,只能从1981年提供的丰富多彩的工作中选几个例子。 Hudrlik和Kulkarni[J.Am.Chem.Soc.,103,6251(1981)]找到了在羰基邻近处引入一个乙烯基的方法。这就是由相应的亚胺通过小心水解制得的α-叔丁基二甲硅基-醛(40)和(41)。它们在与酮和酯的烯醇锂盐反应时,可看作是具有立体选择性的乙烯基阳离子的等同体。例如,频哪酮的反应如下:
Reagents and Synthetic Motifs As syntheses are increasingly active, there is a natural need for synthetic reagents and synthetic motifs that can be used in a variety of applications that can make up the special building blocks. Here, only a few examples can be drawn from the rich and colorful work provided in 1981. Hudrlik and Kulkarni [J. Am. Chem. Soc, 103, 6251 (1981)] found a way to introduce a vinyl group in the vicinity of the carbonyl group. This is a-tert-butyldimethylsilyl-aldehydes (40) and (41) prepared by careful hydrolysis of the corresponding imines. When reacted with keto and ester enol lithium salts, they are considered as stereospecific vinyl cation isomers. For example, the reaction of pinacolone is as follows: