Bicyclo[3.3.1]nonanes as synthetic intermediates. IV. Behavior of bicyclo[3.n.1]alkan-3-ones toward the Baeyer-Villiger oxidation.
作者:TAKEFUMI MOMOSE、OSAMU MURAOKA、SHOHGO ATARASHI、TAMIKO HORITA
DOI:10.1248/cpb.27.222
日期:——
The Baeyer-Villiger oxidation of bicyclo [3. n. 1] alkan-3-ones and related systems is described. Bicyclo [3. 3. 1] nonan-2-one (8) was oxidized into the corresponding lactone, which was found to be converted into the cis-1, 3-disubstituted cyclohexane system by the subsequent methanolysis. Meanwhile, the 3-oxo system (2) manifested an anomalous inactivity against the oxidation. The"backside steric hindrance"caused by the axial (endo) proton at C-7 was postulated as the origin of the inactivity. The differential reactivity of the ketones in the Baeyer-Villiger reaction of the bicyclic systems (2, 3, 4) enabled the regiospecific lactonization of the bicyclic diketones (17, 18, 19) into the lactones (37, 38, 39), which would be important precursors for specifically substituted medium-sized lactones, to be achieved.
描述了双环[3.n.1]烷-3-酮和相关系统的拜耳-维利格氧化。双环[3.3.1]壬烷-2-酮(8)被氧化成相应的内酯,发现通过后续的甲醇解转化为顺式-1,3-二取代环己烷系统。同时,3-氧代系统(2)表现出异常的抗氧化性。假设C-7处的轴向(内)质子引起的“背面空间位阻”是不活跃的根源。在双环系统(2、3、4)的拜耳-维利格反应中,酮