o-bis(6-hydroxy-1,4-dioxahexyl)benzene in methanol by Pyrex-filtered UV light gave the corresponding intramolecular pseudophotodimerized crown ethers, and irradiation of the crown ethers in methanol by 220 nm UV light gave the open chain starting dicinnamates in reverse. The structures of the isolated crown ethers were confirmed to be δ-form by the 1H NMR spectra and X-ray analysis.
用耐热
玻璃过滤的紫外光照射邻双(3-羟基-1-氧杂丙基)苯和邻双(6-羟基-1,4-二氧杂己基)苯的
甲醇溶液,得到相应的分子内假光二聚化
冠醚,并用 220 nm 紫外光照射
甲醇中的
冠醚,得到相反的开链起始二
肉桂酸酯。通过1H NMR光谱和X射线分析证实分离的
冠醚的结构为δ型。