Question

1. Addition reactions (Electropholic reaction)
Unlike isolated dienes, the conjucated dienes like 1,3-Butadine with Br2 give
not only 1, 2 addition product but also to give 1, 4- addition product. The 1, 4-
addition usually predominates.
H2C = CH-CH=CH2+Br2
1,3-Butadine
1, 4 addition
1, 4 -Dibromo - 2 -
Hexane
Butane
-15°C
| 1, 2 -addition
3, 4 -Dibromo - 1 -
Butane​

Answer 1

Answer:

Similar reactions of conjugated dienes, on the other hand, often give unexpected products. The addition of bromine to 1,3-butadiene is an example. As shown below, a roughly 50:50 mixture of 3,4-dibromo-1-butene (the expected product) and 1,4-dibromo-2-butene (chiefly the E-isomer) is obtained.