Question

Write the formulas of the seven doubly brominated isomers formed when 2,2-dimethylbutane reacts with Br2 in the presence of light

Answer 1

Answer : 2,2-dimethylbutane actually has got 3 methyl radicals and 1 ethyl radical attached to the 2nd carbon.

The pairs of positions for the Br atoms are in these ways

(a) both on the far end of the ethyl

`(H_(3)C)_(3) - C - CH_(2) - CHBr_(2)`

(b) both on the near C of the ethyl

`(H_(3)C)_(3) - C - CBr_(2) - CH_(3)`

(c) both on the ethyl but not on the same C

`(H_(3)C)_(3) - C - CHBr - CH_(2)Br`

(d) both on one of the methyls

`(H_(3)C)_(2) (Br_(2)HC) - C - CH_(2) - CH_(3)`

(e) both on methyls, but not the same methyl

`(BrH_(2)C) (H_(3)C)_(2) - C - CH_(2) - CH_(3)`

(f) one on a methyl and one on far end of ethyl

`(H_(3)C)_(2) (BrHC) - C - CH_(2) - CH_(2)Br`

(g) one on a methyl and one on near C of ethyl.

`(H_(3)C)_(2) (BrHC) - C - CHBr - CH_(3)`