Prospects and Progress in Ellagitannin Synthesis

Abstract

The ellagitannin family of secondary plant metabolites presents a rich array of challenges for contemporary organic synthesis. The myriad intra- and inter-molecular coupling modes available to galloyl rings appended to a glucose core, along with a range of post-coupling modifications, define a vast matrix of bond-forming possibilities, many of which are represented within the 500+ structurally characterized members.1–4 A heightened interest in this class of natural products is fueled by recent observations that several ellagitannins display remarkable levels of activity in various anticancer and antiviral assays and hence may serve as promising leads for development of novel therapeutics.3,5–7 Progress toward that goal will benefit from access to significant quantities of natural material as well as designed analogs for delineation of structure/activity profiles and elucidation of biological mechanism-of-action. These latter goals, and possibly the former goal as well, can only be met through a program of total chemical synthesis.