Synthesis 2003(17): 2679-2688  
DOI: 10.1055/s-2003-42440
PAPER
© Georg Thieme Verlag Stuttgart · New York

Alkoxycarbonyl-Substituted 3-Trifloxypropene Iminium Salts and Iminium-Substituted Δ2,3-Butenolides: Synthesis and Reactivity toward Nucleophiles

Joachim Nikolai, Gerhard Maas*
Abteilung Organische Chemie I, Universität Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
Fax: +49(731)5022803; e-Mail: gerhard.maas@chemie.uni-ulm.de;
Further Information

Publication History

Received 22 July 2003
Publication Date:
21 October 2003 (online)

Abstract

Triflic anhydride reacts regioselectively with the ethoxy­carbonyl-substituted enaminones 6a-h to give the novel 3-trifloxy­propene iminium salts 7a-d or iminium-substituted Δ2,3-butenolides 8a-d and 9a-d in good yields. Hydride reduction of the iminium salts 7a,b affords new 2-dialkylamino-4-trifloxy-but-3-enoates 13a,b, while mild hydrolysis generates 2-oxo-4-trifloxy-butenoates 14a,b . Butenolides 8b,d, and 9c react with methyl hydrazine to afford 4-dialkylamino-pyridazin-3(2H)-ones 12a-c.