Question

Question: Show how you would synthesize each compound, beginning with acetylene and any necessary additional reagents.

(a) prop-2-yn-1-ol (propargyl alcohol)

(b) hept-2-yn-4-ol

(c) 2-phenylbut-3-yn-2-ol

(d) 3-methylhex-4-yn-3-ol

Short answer

Answer

(a)

(b)

(C)

(d)

Step-by-step solution

Acetylene

An unsaturated chemical compound in which two carbon atoms are connected through a triple bond with general formula C_nH_2n-2 is known as alkyne.

Acetylene is the first member of the alkyne homologous series having the chemical formula C₂H₂

Synthesis of given compounds beginning with acetylene and reagents

The abstraction of acetylenic hydrogen can obtain acetylide ions from terminal alkyne upon adding a strong base, i.e., sodium amide. This acetylide plays a vital role in acetylene chemistry.

(a) prop-2-yn-1-ol (propargyl alcohol)

The compound prop-2-yn-1-ol can be synthesized by adding sodium amide and formaldehyde to acetylene. The presence of a protic solvent is required.

(b) hept-2-yn-4-ol

The compound hept-2-yn-4-ol can be synthesized by adding sodium amide, methyl iodide, and butyraldehyde to acetylene.

(c) 2-phenylbut-3-yn-2-ol

The compound 2-phenylbut-3-yn-2-ol can be synthesized by adding sodium amide and acetophenone to acetylene.

(d) 3-methylhex-4-yn-3-ol

The compound 3-methylhex-4-yn-3-ol can be synthesized by adding sodium amide, methyl iodide and butan-2-one to acetylene