Synthesis and conformations of dibenzylanthracenes. Evidence for the 1,4-benzylation of anthracene

Abstract

Four new dibenzylanthracenes (1-4) have been prepared by benzylation of anthracene with 2,5-dimethylbenzyl chloride, 2,4,6-trimethylbenzyl chloride, and 2,3,5,6-tetramethylbenzyl chloride or by reacting 9,10bis(chloromethyl)anthracene with p-xylene or mesitylene using Friedel-Crafts reactions. Evidence is presented for the 1,4-benzylation of anthracene which is attributed to steric hindrance effects preventing the attack of 9,10 positions, normally the most reactive. The structural assignments and the conformational preferences of the compounds prepared were achieved by the interpretation of the uv and nmr spectra combined with a priori estimates of the ring current magnetic effects.

Conformations of Bridged Diphenyls. VI. Substituent Effects and Internal Rotation in Triply Ortho-substituted Diphenyl Ethers

“…For ortho-substituted diphenyl ethers and many other bridged diphenyls there is ample evidence to suggest that the twist, H-inside conformations are the most stable (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26). Figure 3, which was prepared in the manner of Gust and Mislow (6), displays all eight possible twist conformers for a triply ortho-substituted diphenyl ether.…”

Untersuchungen der spektroskopischen und elektrochemischen Eigenschaften 9,10‐arylsubstituierter Anthracene. IV. Diskussion der 1H‐ und 13C‐NMR‐Spektren 9,10‐arylsubstituierter Anthracene

“…Abb. 2 einiger 9,lWdisubstituierter Anthracene Ubersicht (schematisch) iiber die chemischen Verschiebungen 6~ und 6~ dungen werden die Verschiebungen von 9,lO-Dimesitylanthracen (6 = 8,06 und 7,20 ppm) und 9,lO-Di-p-xylyl-anthracen (S = 8,12 und 7,41 ppm) [12] betrachtet. Die chemischen Verschiebungen der A-Protonen sind in der Reihenfolge…”