The first conversion of camptothecin to (S)-mappicine by an efficient chemoenzymatic method

Camptothecin has been converted for the first time to (S)-mappicine via mappicine ketone, which is the sole product of the microwave irradiation of camptothecin. Bakerʹs yeast reduction of mappicine ketone yielded (S)-mappicine in high optical purity.