Hello, I'm looking for the specific mechanism by which NaBH4 converts a carbon-carbon double bond to a single bond (hydrogenation) in 2-cyclopentenone. NaBH4 cannot usually reduce a carbon-carbon double bond, such as the double bond in 2-cyclopentenol. Apparently, only a double bond adjacent to a carbonyl can be reduced (I have a feeling that the oxygen double bond folds down). Any ideas?