Total Synthesis of the Proposed Structure of Paraphaeosphaeride C

Abstract

Paraphaeosphaeride C is a demethoxy derivative of phaeosphaeride A and exhibits STAT3 inhibitory activity. Our previous papers reported the total synthesis of phaeosphaeride A using a diastereoselective vinyl anion aldol reaction as the key step to construct the dihydropyran ring. In this work, the first total synthesis of the proposed structure of paraphaeosphaeride C was achieved via a similar synthetic strategy. The synthetic compound was characterized through extensive nuclear magnetic resonance (NMR) analysis but the 1H and 13C-NMR data for this compound did not correspond to those reported in the literature for paraphaeosphaeride C.

Editorial to the Special Issue “Total Synthesis of Natural Products: A Themed Issue Dedicated to Professor Dr. Dieter Schinzer for His 65th Birthday”

“…They are, therefore, considered potential lead compounds for anticancer drug discovery. The communication by Kobayashi et al [ 3 ] describes the synthesis of the proposed structure of paraphaeosphaeride C following a synthesis route similar to the earlier synthesis of a related congener by the same group. The synthesis described in this paper featured a Knochel-Hauser base (TMPMgCl·LiCl)-mediated intramolecular vinyl anion aldol reaction and subsequent appropriate functional group transformations, including regioselective methylenation and stereoselective reduction to establish a critical stereocenter.…”