Total synthesis of phomazarin

Published

Journal Article

A concise total synthesis of phomazarin (1) is detailed enlisting a heterocyclic azadiene inverse electron demand Diels-Alder reaction (1,2,4- triazine → pyridine) for preparation of the fully substituted and appropriately functionalized pyridine C-ring. Thus, [4 + 2] cycloaddition (85%) of triethyl 1,2,4-triazine3,5,6-tricarboxylate (2) with trimethoxyethylene (3) followed by conversion of the cycloadduct 11 to the cyclic anhydride 13 provided the phomazarin C-ring with the three carboxylates suitably differentiated. Linkage of the A- and C-rings through selective nucleophilic addition of the aryllithium reagent 9 to the least hindered anhydride carbonyl of 13 followed by Friedel-Crafts closure of the B-ring provided the fully functionalized phomazarin skeleton. The successful structural correlation of synthetic 1 with natural material and its derivatives confirmed the latest structural assignment for the natural product.

Full Text

Duke Authors

Cited Authors

  • Boger, DL; Hong, J; Hikota, M; Ishida, M

Published Date

  • March 24, 1999

Published In

Volume / Issue

  • 121 / 11

Start / End Page

  • 2471 - 2477

International Standard Serial Number (ISSN)

  • 0002-7863

Digital Object Identifier (DOI)

  • 10.1021/ja983631q

Citation Source

  • Scopus