Reactions of Molecules with Two Equivalent Functional Groups. 5. Anomalous Reactivity of 1,10-Cyclooctadecanedione. Crystal and Molecular Structures of <i>cis</i>,<i>cis</i>-1,10-Diphenyl-1,10-cyclooctadiene and the Stereoisomers of 1,10-Diphenyl-1,10-cyclooctadecanediol<sup>1</sup>
作者:Roger S. Macomber、Ioannis Constantinides、Jeanette Krause Bauer、Gregory Smith、Angela Button、David O. Lindstrom
DOI:10.1021/jo930376d
日期:1996.1.1
6-M is 4.4 times as reactive as each carbonyl in 3. Competition experiments further demonstrate that the relative rates (per carbonyl) for addition of phenylmagnesium bromide to 3, 10-methylenecyclooctadecanone (11), and cyclopentadecanone (12) are 1.0:0.60:1.92. Possible reasons for this order of reactivity are discussed. Diols 7 and 8 undergo facile double dehydration to form the title diene 13, which
标题二酮(3)与苯基格氏试剂的反应生成(速率常数为k(1))10-羟基-10-苯基环十八烷酮(6)的共轭碱(6-M),随后将其转化为速率常数k(2))作为顺式(7,55%)和反式(8,45%)异构体的混合物的标题二醇的共轭碱。k(2)/ k(1)之比为2.2 +/- 0.4,表明6-M中的羰基是3中每个羰基的4.4倍。竞争实验进一步表明,相对速率(每个羰基)对于将苯基溴化镁加成至3,10-亚甲基环十八烷酮(11)和环十五烷酮(12)为1.0:0.60:1.92。讨论了这种反应顺序的可能原因。二元醇7和8容易进行两次脱水以形成标题二烯13 根据分子力学计算,它是四种可能的对称二烯异构体中最稳定的。通过单晶X射线研究确定了7、8和13的结构。