Comparative study of neighboring group participation in reactions of N-bromoor N-chlorosuccinimide on methyl isoricinoleate.

Reacting methyl isoricinoleate with N-bromosuccinimide in the presence of excess diols [mono-, di-, tri-, and tetraethylene glycol] gave the 1,4-epoxy derivative in 80% yield along with the respective ß-bromoethoxylates as minor products (20%). However, when the reaction was carried out with N-chlorosuccinimide, the yield of 1,4-epoxy derivative was reduced to 20%, and formation of ß-chloroethoxylates was increased to 80%. [ABSTRACT FROM AUTHOR]