Expeditious syntheses of conjugated allenyl esters and oxazoles through a cascade reaction of alpha-alkynyl malonates under alkaline conditions.
Diethyl alpha-alkynyl-alpha-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 alpha-alkynyl-alpha-acetylaminomalonates (5a, b, d, e) furnished unexpectedly the oxazoles (7a, b, d, e) having three substituent groups in excellent yields.
Sano
Shigeki
S
Graduate School of Pharmaceutical Sciences, The University of Tokushima, Japan.
Shimizu
Hisashi
H
Kim
Kweon
K
Lee
Woo Song
WS
Shiro
Motoo
M
Nagao
Yoshimitsu
Y
D000468:Alkalies; D000480:Alkynes / Q000138:chemical synthesis*; D032701:Biomimetics; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004952:Esters / Q000138:chemical synthesis*; D006868:Hydrolysis; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008314:Malonates / Q000138:chemical synthesis*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D010080:Oxazoles / Q000138:chemical synthesis*; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism
D000468:Alkalies; D000480:Alkynes; D015853:Cysteine Proteinase Inhibitors; D004952:Esters; D007202:Indicators and Reagents; D008314:Malonates; D010080:Oxazoles