How to prepare ethanal from ethyne by shortest method?

To prepare ethanal (acetaldehyde) from ethyne (acetylene) using the shortest method, you can follow a two-step process:

Step 1: Hydrochlorination of Ethyne to Vinyl Chloride
Ethyne can be converted to vinyl chloride through a hydrochlorination reaction. Here's how to do it:

Ingredients:

Ethyne (C2H2)
Hydrochloric acid (HCl)
Catalyst (usually a copper-based catalyst like copper(I) chloride, CuCl)
Procedure:

Set up a reaction vessel equipped with a suitable condenser.
Mix ethyne gas with a stream of dry hydrogen chloride (HCl) gas in the presence of a copper-based catalyst.
Heat the mixture to a suitable temperature (around 200-250°C) to initiate the hydrochlorination reaction.
Collect the product, which is vinyl chloride (C2H3Cl), as it distills over.
Step 2: Oxidation of Vinyl Chloride to Ethanal
Once you have obtained vinyl chloride, you can oxidize it to ethanal. Here's the oxidation reaction using a common oxidizing agent:

Ingredients:

Vinyl chloride (C2H3Cl)
An oxidizing agent (such as potassium permanganate, KMnO4, or chromic acid, H2CrO4)
Acid (typically sulfuric acid, H2SO4)
Procedure:

Set up a reaction vessel equipped with a condenser.
Place vinyl chloride in the reaction vessel.
Add the oxidizing agent (KMnO4 or H2CrO4) and acid (H2SO4) to the reaction vessel.
Heat the mixture gently while stirring. The oxidation reaction will occur, converting vinyl chloride into ethanal.
Distill the product, ethanal (CH3CHO), as it forms and passes over the condenser.
Ensure safety precautions are followed when working with chemicals, and be mindful of the potential hazards associated with the reagents and reactions involved. This two-step process allows you to convert ethyne into ethanal efficiently.