Investigation of the Cyclopentenone Formationvia the ?-Alkynone Cyclisation: Synthesis of the Acorone Intermediate 8-Methylspiro[4.5]deca-3,7-dien-2-one
作者:John Ackroyd、Martin Karpf、Andr� S. Dreiding
DOI:10.1002/hlca.19850680208
日期:1985.3.27
of the cyclopentenone formation ACvia the thermal α-alkynone cyclisation BC and in order to test the fate of an isolated C,C-double bond within a molecule under these conditions, we investigated the synthesis of the acorone intermediate 3starting from the known carboxylic acid 1. The α-alkynone 2 was obtained from 1via the acyl chloride 6 and a Pd(II)-catalysed route (22%). The thermolysis of 2 at
作为环戊烯酮形成的另一应用AC经由热α-炔酮环化BC和为了测试的分离的C的命运,在这些条件下的分子内C-双键,我们调查了acorone中间体的合成3起始由已知的羧酸1。通过酰氯6和Pd(II)催化的途径(22%)从1获得α-炔酮2。2在550°的热解提供了目标分子3(48%)以及竞争性分子内烯反应及其二聚体的产物9(20%)10(4%)。在较高的热分解温度(650℃),螺环酮3被发现是不稳定的,得到的复古-狄尔斯-阿尔德片段4-亚甲基-2-环戊烯酮(12)(33%)和异戊二烯(32%)。分离的双键对环戊烯酮形成序列AC收率的影响的另一个例子是通过将环化作用1420(Pd(II)催化的酰化作用总量为5%)与其非烯属化反应的作用进行比较而提供的。类似物1721(Friedel - Crafts酰化剂占53%)。