Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

Addition of methanol or ethanol to perfluoro-1,3-butadiene (I), catalysed with sodium alkoxide, afforded a mixture of the corresponding alkyl 4-alkoxy-3,4,4-trifluoro-2-butenoate VIb or VIa, dialkyl 2-fluorofumarate VIIb or VIIa, and dialkyl 2-alkoxy-2-butene-dioate IXb or IXa, in the overall yield 83% or 93%. The addition of propanol to the diene I in the presence of sodium propoxide gave dipropyl fluorofumarate (VIIc) as the sole product in 92% yield.. The course of the addition is suggested and discussed. The compound VIa was transformed into ethyl 3,4-diethoxy-4,4-difluoro-2-butenoate (VIIIa), diethyl 2-fluorofumarate (VIIa), diethyl 2,3-dibromo-2-fluorosuccinate (XI) and ethyl 3-amino-4-ethoxy-4,4-difluoro-2-butenoate (XIII). The compound VIIa afforded the succinate XI, diethyl 2,2-diethoxysuccinate (X) and 2-amino-2-butenediamide (XIV). Diethyl 2-ethoxy-2-butenedioate (IXa) was converted to diethyl 2,3-dibromo-2-ethoxysuccinate (XII) and the succinate X. The ¹H- and ¹⁹F-NMR spectra afforded information about the structure of the prepared compounds.