Abstract:
H-D exchange at the formyl residue of the natural product malonganenone B was investigated.
Models of the system were synthesised and displayed the same exchange. Kinetic studies, performed using NMR spectroscopy, found the exchange was first
order with respect to base whilst displaying acid inhibition, in opposition to existing research. Cyclic species, including an N-heterocyclic carbene precursor, were formed that, in conjunction with the previous findings, suggested a carbene-based
mechanism was in operation. Further synthetic studies were performed to demonstrate the existence of a carbene. With use of silver oxide, a fulvalene dimer and an organopalladium complex of this carbene were obtained, which provide further
support towards a carbene-based mechanism being involved in the H-D exchange of malonganenone B.
