( ( The ( final step ) ) ( ( involves ( a ( reverse-aldol ( reaction ( to ( break ( ( the bond ) ( between ( the ( ( ( alpha and ) beta ) carbons ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (JJ final) (NN step)) (VP (VBZ involves) (NP (DT a) (JJ reverse-aldol) (NN reaction) (S (VP (TO to) (VP (VB break) (NP (NP (DT the) (NN bond)) (PP (IN between) (NP (DT the) (ADJP (NN alpha) (CC and) (NN beta)) (NNS carbons))))))))) (. .)))
The final step involves a reverse-aldol reaction to break the bond between the alpha and beta carbons.
(ROOT (S (NP (JJ Catabolic) (NNS reactions)) (VP (VBP involve) (S (VP (VBG breaking) (NP (NNS bonds))))) (. .)))