The stereoselective synthesis of an aryl vinyl bromide is accomplished in a rapid microscale reaction of "trans"-4-methoxycinnamic acid with N-bromosuccinimide in dichloromethane. The product is purified by dry column vacuum chromatography and its stereochemistry is determined by [superscript 1]H NMR. TLC, GC and GC-MSD can also be used. This guided-inquiry experiment links reactivity, stereochemistry, and mechanism in electrophilic addition reactions of alkenes and in E1 and E2 elimination reactions that form alkenes. (Contains 3 schemes and 1 figure.)