作者:Bridget McCarthy Cole、Luning Han、Barry B. Snider
DOI:10.1021/jo961199u
日期:1996.1.1
free-radical cyclization of unsaturated ketones is a versatile synthetic procedure with broad applicability. For example, oxidation of cyclopentanone 1a with 2 equiv of Mn(OAc)(3).2H(2)O and 1 equiv of Cu(OAc)(2).H(2)O in AcOH at 80 degrees C for 1.5 h affords 75% of bicyclo[3.2.1]oct-3-en-8-one 8a and 15% of bicyclo[3.2.1]oct-2-en-8-one 9a. Bridged bicyclic ketones that cannot enolize further are isolated
Mn(III)基的不饱和酮的氧化自由基环化是一种通用的合成方法,具有广泛的适用性。例如,在80摄氏度的条件下,在AcOH中用2当量的Mn(OAc)(3).2H(2)O和1当量的Cu(OAc)(2).H(2)O氧化环戊酮1a 1.5小时得到75%的双环[3.2.1] oct-3-en-8-one 8a和15%的双环[3.2.1] oct-2-en-8-one 9a。分离出不能进一步烯醇化的桥联双环酮,收率很高。可以烯化的单环β,γ-不饱和酮被进一步氧化,得到γ-乙酰氧基烯酮。从2-烯丙基环己酮(56a)以52%的收率形成双环[3.3.1] non-2-en-9-one(57a)表明,动力学控制的烯醇化是α-酮自由基形成过程中的决定速率的步骤。各种各样的示例描述了范围,限制,