A Simple Route to Racemic Acenaphtencarboxylic Acid via Hydroformylation of Acenaphthylene

Hydroformylation of acenaphthylene using di-mu-chlorotetracarbonyldirhodium/triphenylphosphine as catalytic precursor affords acenaphthene-1-carboxaldehyde under mild conditions in 80 % yield. This compound is easily transformed, via dehydration of the corresponding oxime followed by hydrolysis of the nitrile, into acenaphthene-1-carboxylic acid in an overall yield of ~ 50%.