1,2-vs.1,4-Addition Br H HBr CH2=CH-CH-CH2 CH2=CH-CHCH2 BrCH2-CH=CH-CH2 4321 21 4 1 kine tic the rmodynamic forms more rapidly is more stable 1,2- vs. 1,4-Addition 4 3 2 1 2 1 4 1 H H kinetic thermodynamic C H2 =CH-CH=CH2 HBr C H2 =CH-CHCH2 Br BrCH2 -CH=CH-CH2 forms more rapidly is more stable