ISOLATION AND RELATIVE REACTIVITIES IN CHROMIUM(VI) OXIDE OXIDATION OF THE ROTAMERS OF 9-(2-FORMYL-1-NAPHTHYL)FLUORENE AND RELATED ALCOHOLS
作者:Michinori Oki、Ryo Saito
DOI:10.1246/cl.1981.649
日期:1981.5.5
and 9-[2-(α-hydroxybenzyl)-1-naphthyl]fluorene showed that the relative reactivities of the rotamers of the former were almost the same, while those of the latter differed to a great extent. The results suggest that the steric hindrance to the approach of a base to a proton in E2 elimination is the cause of poor reactivities of the ap forms of the aldehyde and the benzylic alcohol.
分离出9-(2-甲酰基-1-萘基)芴的旋转异构体(sp 和ap)。旋转(sp → ap)的ΔH\eweq 和ΔS\eweq 分别为24.0 kcal mol-1 和-7.9 eu。sp 形式的氧化平稳地提供相应的羧酸,而 ap 形式反应非常缓慢,得到内酯。9-(2-羟甲基-1-萘基)芴和9-[2-(α-羟基苄基)-1-萘基]芴的氧化表明,前者的旋转异构体的相对反应活性几乎相同,而后者差别很大。结果表明,在 E2 消除中,碱基接近质子的空间位阻是醛和苯甲醇的 ap 形式反应性差的原因。