Preparation of N-(alk-1-enyl) nucleobase compounds by Horner and Horner–Wadsworth–Emmons reactions
作者:Thomas Boesen、Christian Madsen、Ulla Henriksen、Otto Dahl
DOI:10.1039/b002744h
日期:——
A series of new N9-(alk-1-enyl)adenines and N1-(alk-1-enyl)thymines has been prepared by Horner reactions of the new phosphine oxides N9-(diphenylphosphorylmethyl)adenine and N1-(diphenylphosphorylmethyl)thymine derivatives 13aâc, or HornerâWadsworthâEmmons reactions of the corresponding new phosphonates 14aâb, with benzaldehyde and various ketones. Yields were highest for the Horner reactions (10â79%), and were limited by steric hindrance, enolization of the ketones, and decomposition of some of the N1-(alk-1-enyl)thymines in the presence of excess base (NaH). Butanal gave mixtures of products under Horner conditions, probably because aldol reactions intervened.
一系列新的N9-(烯-1-基)腺嘌呤和N1-(烯-1-基)胸腺嘧啶通过Horner反应制备,该反应以新的氧化膦衍生物N9-(二苯基膦酰甲基)腺嘌呤和N1-(二苯基膦酰甲基)胸腺嘧啶衍生物13a–c为原料,或者通过相应的新的膦酸酯14a–b与苯甲醛和各种酮进行Horner-Wadsworth-Emmons反应。Horner反应的产率最高(10-79%),但由于立体位阻、酮的烯醇化和在过量碱(NaH)存在下某些N1-(烯-1-基)胸腺嘧啶的分解,产率受到限制。正丁醛在Horner条件下产生混合产物,可能是因为发生了醇醛反应。