Question

In each reaction box, place the best reagent and conditions from the list below.

In each reaction box, place the best reagent and conditions from the list below 1) 2) 3) 4) PBrs H2, Lindlar catalyst Вн-THF CH5CH2Br NaBH4 CH3Br H2O, H2SO4, HgSO4 Na, NHa () НаОг, NaOH, Hzо excess NaNH2 HBr Br2 2 equiv. NaNH2

Answer 1

1) Br₂

2) excess NaNH₂

3) CH₃Br

4) Na, NH₃ (l)

Explanation: Reaction of alkene with Br2 produces dibromo compound as product. NaNH2 is a strong base which gives dehydrohalogenation and produces acetylide ion which on further reaction with alkyl halide produces an extended carbon chain as product. Reduction of alkyne with Na, NH3(l) produces trans-alkene as product.