interactions between the carbonyls and a methoxyl or a chlorogroup and are discussed from the electron-accepting ability of the carbonyl group and the electron-donating ability of the methoxyl and the chlorogroups. An aldehyde group was apparently less able to interact with electron-donors than a ketone. This apparent anomaly was discussed from the intramolecular dipolar interactions.
已经制备了在三苯乙烯系统的 1-位带有甲氧基或氯基团并在 9-位带有取代的羰基甲基的化合物,以通过 1 H NMR 光谱检查旋转异构体的群体。甲氧基化合物有利于±sc 构象,而p 构象在氯化合物中相对有利。结果表明羰基与甲氧基或氯基之间存在吸引相互作用,并从羰基的受电子能力和甲氧基和氯基的给电子能力进行讨论。与酮相比,醛基与电子供体的相互作用显然更弱。从分子内偶极相互作用讨论了这种明显的异常。
Facile Intramolecular Cyclization Reactions of Aromatic Ethers with Cationoids in Triptycene Systems
1,4-Dimethoxytriptycenes were found to give cyclic ethers with unusual ease when a substituent at the bridgehead bears a cationoid center. The easy reaction is attributed to the extreme proximity between the methoxyl group and the cationic center. Mechanisms involving a cyclic oxonium ion and subsequent attack by an anion to produce the cyclic ether and a methyl derivative are discussed.