Various anti-9-methoxy[3.3]metacyclophane-2,11-diones are exclusively obtained by the coupling reaction of the corresponding 1,3-bis(bromomethyl)benzenes and 2,6-bis[2-isocyano-2-(tolylsulfonyl)ethyl]-4-tert-butylanisole in dimethylformamide (DMF) with an excess of sodium hydride, from which the corresponding syn-[3.3]metacyclophanes (MCPs) are synthesized via anti/syn-isomerization during the Wolff–Kishner reduction. Demethylation of syn-9-methoxy[3.3]MCPs with BBr3 afforded the corresponding syn-9-hydroxy[3.3]MCPs in good yields. The existence of the strong intramolecular hydrogen bonding between the 9-hydroxy group and the 18-substituents, such as F, OH, and OMe groups at the opposing aromatic rings, are observed in solution and in the solid state. A distinct low-field shift of the phenolic OH proton was observed in the 1H NMR spectrum compared with that of the 18-unsubstituted analog. Furthermore, O–H···F through-space coupling was observed.
各种抗9-甲氧基[3.3]甲基环戊烷-2,11-二酮是通过对应的1,3-双(溴甲基)苯和2,6-双[2-异氰基-2-(甲苯磺酰基)乙基]-4-叔丁基苯醚在二甲基甲酰胺(DMF)中与过量的氢化钠进行偶联反应而独家获得的,从中通过 Wolff–Kishner 还原过程中的反/同构异构化合成相应的同-[3.3]甲基环戊烷(MCPs)。用BBr3对同-9-甲氧基[3.3]MCPs进行去甲基化反应,得到相应的同-9-羟基[3.3]MCPs,收率较高。在溶液和固态中观察到9-羟基与18-取代基之间的强分子内氢键存在,例如对位芳香环上的F、OH和OMe基团。与18-未取代类似物相比,在1H NMR谱中观察到酚羟基质子的明显低场位移。此外,观察到了O–H···F的空间耦合。