Expeditious Syntheses of Conjugated Allenyl Esters and Oxazoles through a Cascade Reaction of .ALPHA.-Alkynyl Malonates under Alkaline Conditions
作者:Shigeki Sano、Hisashi Shimizu、Kweon Kim、Woo Song Lee、Motoo Shiro、Yoshimitsu Nagao
DOI:10.1248/cpb.54.196
日期:——
Diethyl α-alkynyl-α-methoxymalonates (2a—e) were smoothly hydrolyzed and then decarboxylated under alkaline conditions employing 1 N KOH in EtOH to give conjugated allenyl esters (6a—e) in high yields, and similar alkaline treatment of diethyl α-alkynyl-α-acetylaminomalonates (5a, b, d, e) furnished unexpectedly the oxazoles (7a, b, d, e) having three substituent groups in excellent yields.
α-炔基-α-甲氧基丙二酸二乙酯 (2a-e) 在碱性条件下使用 1 N KOH 的 EtOH 溶液顺利水解,然后脱羧,以高产率得到共轭丙二烯基酯 (6a-e),并且对α-炔基-α-乙酰氨基丙二酸二乙酯(5a、b、d、e)进行类似的碱处理,意外地以优异的产率提供了具有三个取代基的恶唑(7a、b、d、e)。