For the reaction below, which of the alkynes listed would be expected to produce the product under the conditions shown?

Question

Quizplus · Accepted Answer

The given reaction is a hydroboration-oxidation reaction, which adds H and OH across the triple bond to form an alcohol. The regioselectivity of the reaction follows Markovnikov's rule, meaning the H adds to the carbon with fewer hydrogens and the OH adds to the carbon with more hydrogens. In this case, the initial product formed after hydroboration will be a vinylborane (BH2-CH=CH2). The vinylborane can then be converted to the alcohol by oxidation with hydrogen peroxide and a base. Out of the given alkynes, only option C has an unsymmetrical triple bond, meaning it has a carbon with fewer hydrogens and a carbon with more hydrogens. This will allow for the regioselective addition of H and OH to form the desired alcohol product.

For the Reaction Below, Which of the Alkynes Listed Would