Final answer:
The hydroboration-oxidation of a terminal alkyne leads to the formation of an aldehyde functional group, which contains a carbonyl group bonded to a hydrogen atom.
Step-by-step explanation:
The hydroboration-oxidation of a terminal alkyne typically results in the formation of an aldehyde functional group. This reaction involves the addition of borane (BH3 or its derivatives) to the alkyne, followed by oxidation with hydrogen peroxide (H2O2) in the presence of a base, usually sodium hydroxide (NaOH). Terminal alkynes specifically give aldehydes due to the anti-Markovnikov addition of water across the triple bond in the intermediate organoborane species, placing the hydroxyl group on the more substituted carbon. This is in contrast to internal alkynes, where a ketone would be the typical outcome.
Aldehydes are characterized by a carbonyl group (a carbon-oxygen double bond) where the carbonyl carbon is bonded on one side to a hydrogen atom. When naming aldehydes, the '-al' suffix is used.