Question

Reaction of one molecule of HBr with one molecule of 1, 3 - butadiene at 40°C gives predominantly
(a) 3 - bromobutene under kinetically controlled conditions
(b) 1 - bromo - 2 - butene under thermodynamically controlled conditions
(c) 3 - bromobutene under thermodynamically controlled conditions
(d) 1 - bromo - 2 - butene under kinetically controlled conditions.

Answer 1

(b) : 1,2 - addition product is kinetically controlled product while 1,4 - addition product is thermodynamically controlled product and formed at comparatively higher temperature.