Question

How can the following compounds be prepared using ethyne as the starting material?

Short answer

Acetal dehyde can be prepared using ethyne as the starting material and by using H₂O, H₂SO₄, HgSO₄ as reagents.

Step-by-step solution

Step1: Preparing compounds by using ethyne for part (a)

Acetal dehyde can be prepared using ethyne as the starting material and by using H₂O, H₂SO₄, HgSO₄ as reagents.

Step 2: Preparing compounds by using ethyne for part (b)

Propan-2-one can be prepared using ethyne as the starting material and by using NaNH₂, CH₃CH₂Br and H₂/Lindlar catalyst as reagents.

Step 3:Preparing compounds by using ethyne for part (c)

1,2-dibromobutane can be prepared using ethyne as the starting material and by using NaNH₂, CH₃Br and H₂O, H₂SO₄, HgSO₄ as reagents.

Step 4: Preparing compounds by using ethyne for part (d)

(E) Pent -2-ene can be prepared using ethyne as the starting material and by using NaNH₂, CH₃Br and Na, NH₃ (liq) as reagents

Step 5: Preparing compounds by using ethyne for part (e)

(Z) Pent-2-ene can be prepared using ethyne as the starting material and by using NaNH₂, CH₃Br and NaNH₂, CH₃CH₂Br as reagents.

Step 6:  Preparing compounds by using ethyne for part (f)

Pentane can be prepared using ethyne as the starting material and by using NaNH₂, CH₃Br and excess H₂, Pd/C as reagents.