Question

The reagent(s) required for the conversion of hex-3-yne to (E)-hex-3-ene is/are:

• A. H\(_2\), Pd/BaSO\(_4\)
• B. Bu\(_3\)SnH
• C. Li / liquid NH\(_3\)
• D. LiAlH\(_4\)

Hint:

The reduction of alkynes to trans-alkenes can be achieved using lithium in liquid ammonia, a well-known anti addition reaction.

Answer 1

The Correct Option is C

The reaction involves the conversion of hex-3-yne to (E)-hex-3-ene. The correct reagent for this transformation is Li in liquid NH\(_3\), which induces a reaction known as the reduction of a terminal alkyne to a trans-alkene (E-isomer).

Step 1: The reaction requires a strong reducing agent like lithium in liquid ammonia, which facilitates the anti addition of hydrogen across the triple bond, resulting in the formation of the (E)-alkene.

Step 2: The other options are incorrect because they either involve different reactions or do not lead to the desired product.

Final Answer: Li / liquid NH\(_3\).