Acetic Anhydride → 6-Heptenoic acid

Participants

Reaction Conditions

Reaction Steps

In a procedure similar to example 3, a mixture of suberic acid (20.0 g, 0.115 mol), acetic anhydride (11.7 g, 0.115 mol) , and chlorocarbonyl bis(dimethylphenylphospine)rhodium (0.509 g, 0.00115 mol) was heated under reduced pressure (100 torr) using an oil bath maintained at 255° C. and the product collected as it distilled from the reactor. The material removed was continuously replaced with a mixture of suberic acid and acetic anhydride (1:1 molar mixture; a total of 90.0 g of suberic acid was used in the feed mixture) in a rate that maintained the initial level of the reactor contents throughout the course of the entire reaction. The formation of product ceased after about 90 minutes of reaction time. The distillate product collected was fractionally distilled to provide 54.1 g of 6-heptenoic acid (bp 95°-100° C./10 torr) which was found by GC analysis to be >98% of the α-olefin. This amount of product corresponds to a catalyst TON of 368. Considering the amount of unreacted suberic acid containing residue recovered in the distillation pot (19.6 g), the isolated yield of 6-heptenoic acid relative to the suberic acid in the feed mixture was nearly quantitative.

Provenance & Evidence