The Total Synthesis of Retrojusticidin B, Justicidin E, and Helioxanthin.

Making use of a tandem free radical cyclization process mediated by Mn(OAc)3 as a key operation, the total synthesis of retrojusticidin B, justicidin E, and helioxanthin has been concisely achieved in four or five steps in an overall yield of 45, 33 and 44%, respectively, from a common starting material 5. [ABSTRACT FROM AUTHOR]