3-Bromo-2,5-dihydrofuran-2-one and 4-Bromo-2,5-dihydrofuran-2-one

Abstract

Although 3-bromo-2,5-dihydrofuran-2-one and 4-bromo-2,5-dihydrofuran-2-one were first reported in 1894, considerable ambiguity still exists about the correct structure assignment of the two compounds. The present article gives a brief overview on the varying assignments of constitution and describes a novel method for the formation of 3-bromo-2,5-dihydrofuran-2-one. A comparison is made of the experimental 13C NMR chemical shifts with values predicted by increment calculations and experimental 1JC-C coupling constants are given for both compounds. Secure structural assignments are now available for both isomers.