The Second Total Synthesis of Diazonamide A

The uniquely woven, highly strained molecular architecture and the potent antitumor activity of diazonamide A (1) make this natural product an attractive synthetic target. The key steps in this total synthesis of 1 include a novel SmI2-induced ring-closing cascade sequence and an unusual oxidation of an indoline to an oxindole in the presence of Pd(OH)2/C.