Abstract
Halohydrin esters are potentially versatile synthetic reagents, but their conventional
synthesis commonly involves hazardous ethylene oxide. An economic, mild, safe, and
scalable one-step halohydrin esters synthesis was achieved from easily accessible
NaX, concentrated sulfuric acid, and polyol esters. The halohydrin ester products
were applied in hydroxyethylation reactions with various nucleophiles in place of
highly hazardous and toxic ethylene oxide. Repetition of the protocol allowed unsymmetric
difunctionalization of diol esters. The mechanism likely involves an acyloxonium intermediate
and proceeds through neighboring group participation.
Key words
halohydrin esters - hydroxyethylation - sodium bromide - ethylene oxide - acyloxonium.
