3'甲酰基苯并冠醚的合成

本文用邻香兰醛作为起始原料,经过脱甲基反应,而制得2,3-二羟基苯甲醛,然后,在DMF中分多甘醇二对甲苯磺酸脂和氢方钠(方法A)或多醉二醇二氯化物和碳酸钾(方法B)长时间加热反应,即合成了3'-甲酰锘苯并冠醚和3',3'-和3'6'-二甲酰基二苯并冠醚.

Syntheses of 3'-formylbenzocrown ethers

3'-Formylbenzocrown ethers I (n = 1, 2, 3) and 3',3'-diformyldibenzocrown ethers II (n = 1, 2, 3) were synthesized from 2,3-dihydroxybenzaldehyde with polyethylene glycol ditosylates and NaH in DMF (method A) or polyethylene glycol dichlorides and K2CO3 in DMF (method B) resp. By method A, the acyclic intermediates III (n = 1, 2) were also isolated from the reaction products. II (n = 1) prepared by method B was separated into the syn and anti isomers by further column chromatog. The cause concerning the reluctance of the reactions and the poor yields of the products is discussed in detail. It may be due to the presence of the formyl group on the benzene ring which would provide the neighboring hydroxyl group with a stronger acidity and then its anion with a weaker nucleophilicity.