The effect of amines on the selective bromination of some β- substituted-2-butenoic esters is described. The bromination of methyl (Z)4-t- butyldiphenylsilyloxy-3-methylbutenoate 2 in the presence of DIPEA (N, N- diisopropylethylamine) and the successive treatment of the obtained dibromide with potassium t-butoxide afford the desired Z bromide selectively. But the corresponding E bromide forms exclusively when 2, 6-di-t-butyl-4- methylpyridine is used in the bromination.
ASJC Scopus subject areas
- Organic Chemistry