Regio- and Stereoselective Cyclopentannulation with Ketones and Propargyl Alcohol Derivatives. Synthesis of<i>dl</i>-Nootkatone and<i>dl</i>-Muscopyridine
作者:Tamejiro Hiyama、Masaki Shinoda、Hiroyuki Saimoto、Hitosi Nozaki
DOI:10.1246/bcsj.54.2747
日期:1981.9
treatment with sulfuric acid–methanol (1:1) at 0 °C. As the major product, 1-methylbicyclo[5.3.0]dec-6-en-8-one was produced from 2-methylcycloheptanone. Remarkable regioselective cyclopentannulation was observed in 2-methylcyclohexanone and 2,3-dimethylcyclohexanone wherein 1-methyl- and trans-1,2-dimethyl-substituted bicyclo[4.3.0]non-5-en-7-one (BNO) are produced, respectively. With 3-butyn-2-ol, 2-methylcyclohexanone
描述了一种高度区域和立体选择性的五元环环化,涉及酮的炔丙醇二阴离子加合物的酸处理。通过在 0°C 下用硫酸-甲醇 (1:1) 处理,2-辛酮的炔丙醇加合物转化为 2-甲基-3-戊基-2-环戊烯酮。作为主要产物,1-甲基双环[5.3.0]dec-6-en-8-one由2-甲基环庚酮生产。在 2-甲基环己酮和 2,3-二甲基环己酮中观察到显着的区域选择性环戊环化,其中产生了 1-甲基-和反式-1,2-二甲基取代的双环 [4.3.0] 非 5-en-7-one (BNO) , 分别。使用 3-butyn-2-ol,2-甲基环己酮被转化为顺式 1,9-二甲基取代的 BNO。4-异丙基-2-甲基环己酮转化为83-85:17-15的c-3-异丙基-γ-1混合物,c-9-二甲基-BNO 及其 3-差向异构体。这些结果用热力学上最有利的羟基戊二烯基阳离子中间体的旋转闭环来解释。3...