Restricted Rotation Involving the Tetrahedral Carbon. XVI. Isolation of Stable Rotamers about an sp<sup>3</sup>-sp<sup>3</sup>Carbon Bond
作者:Gaku Yamamoto、Mikio Nakamura、Michinori Oki
DOI:10.1246/bcsj.48.2592
日期:1975.9
Both antiperiplanar and synclinal rotamers resulted from the restricted rotation about a C–C single bond between the bridgehead t-alkyl group and the skeleton of 9-(1,1-dimethyl-2-phenylethyl)-11-methoxycarbonyl-9,10-dihydro-9,10-ethenoanthracene-12-carboxylic acid are isolated. Optical resolution of the synclinal rotamer is successfully performed by way of the mono-(−)-menthyl esters and a pair of
反周向旋转异构体和向斜旋转异构体均由桥头叔烷基与 9-(1,1-二甲基-2-苯乙基)-11-甲氧基羰基-9,10-骨架之间的 C-C 单键旋转受限引起分离出二氢-9,10-乙烯蒽-12-羧酸。向斜旋转异构体的光学拆分成功地通过单-(-)-薄荷酯和一对酸的对映异构体 [α]D32±24.7° 被分离为稳定实体。发现二甲酯旋转异构体之间相互转化的活化能为 33.2 kcal/mol,频率因子为 1013.3 s-1。