Acetic Acid → 3,4-Diacetoxy-1-butene

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A 100-mL autoclave was charged with 45.25 g (0.44 mol) acetic anhydride, 1.62 g (0.016 mol) of triethylamine, 1.94 g (0.032 mol) acetic acid and 3.44 g of diglyme. The autoclave was purged with helium twice, then the vessel was pressurized to 6.2 bars (75 psig) with helium followed by agitation. The reaction mixture was heated to 125° C. Then 31.35 mL (0.40 mol) of 3,4-epoxy-1-butene was introduced to the reactor via syringe pump over 10 seconds. A first sample was taken at 1 min, then sequential samples were obtained every 15 min during the course of 2.25 hrs for analysis by GC. GC analysis of the crude mixture after 2.25 hrs revealed a 93% yield of 3,4-diacetoxy-1-butene with a 95% selectivity and 1.9% 3,4-epoxy-1-butene. The reaction was observed to be first order in 3,4-epoxy-1-butene with a first order rate constant of 0.029 min-1 (Table A). This example demonstrates the catalytic effect of a tertiary amine with two molar equivalents of acetic acid as a co-catalyst (Table B).

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