The resolution of racemic 4-hydroxy[2.2]paracyclophane (1) by fractional crystallization of the diastereomeric esters 3 with (1S)-(−)-camphanic acid and the determination of the absolute configurations of (R)- and (S)-4-hydroxy[2.2]paracyclophanes by X-ray diffraction have been carried out. The Friedel−Crafts oxaloylation of 1 with AlCl3 was found to occur with formation of both ortho- and para-hydroxy[2.2]paracyclophanylglyoxylic acids, whereas in the presence of TiCl4, quantitative formation of 2,3-dioxo-2,3-dihydrofurano[4,5-d][2.2]paracyclophane (8) as a product of an unusual cooperative C- and O-acylation was observed. Replacement of the OH group in the substrate for OCH3 (compound 18) changes the regioselectivity of the oxaloylation, which now occurs with formation of a para-substituted α-diketone 19. A novel technique for the synthesis of 4-formyl-5-hydroxy[2.2]paracyclophane (FHPC, 15) involving stereoselective reduction of 8 followed by oxidative cleavage of the intermediate diol 14 is also presented.

中文翻译：

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4-羟基[2.2]对环烷的拆分和新反应

通过非对映体酯 3 与 (1S)-(-)-莰酸的分级结晶以及确定 (R)- 和 (S)- 的绝对构型来拆分外消旋 4-羟基 [2.2] 对环烷 (1) 4-羟基[2.2]对环芳烃的X射线衍射已经进行。发现 1 与 AlCl3 的 Friedel-Crafts 草酰化反应同时形成邻羟基[2.2] 对环芳基乙醛酸，而在 TiCl4 存在下，定量形成 2,3-二氧代-2,3-二氢呋喃观察到 [4,5-d][2.2] 对环烷 (8) 作为不寻常的 C-和 O-酰化协同产物。OCH3（化合物 18）底物中的 OH 基团的替换改变了草酰化的区域选择性，现在发生对位取代的 α-二酮 19 的形成。