Revised Structure of Tolyporphin A

Thomas G Minehan; Laura Cook-Blumberg; Yoshito Kishi; Michèle R Prinsep; Richard E Moore

doi:10.1002/(SICI)1521-3773(19990401)38:7<926::AID-ANIE926>3.0.CO;2-W

Revised Structure of Tolyporphin A

Angew Chem Int Ed Engl. 1999 Apr 1;38(7):926-928. doi: 10.1002/(SICI)1521-3773(19990401)38:7<926::AID-ANIE926>3.0.CO;2-W.

Authors

Thomas G Minehan¹, Laura Cook-Blumberg¹, Yoshito Kishi¹, Michèle R Prinsep², Richard E Moore³

Affiliations

¹ Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138 (USA), Fax: (+1) 617-495-5150.
² Department of Chemistry, University of Waikato, Private Bag 3105, Hamilton (New Zealand).
³ Department of Chemistry, University of Hawaii, Honolulu, HI (USA).

PMID: 29711874
DOI: 10.1002/(SICI)1521-3773(19990401)38:7<926::AID-ANIE926>3.0.CO;2-W

Abstract

Four monocyclic precursors were assembled in the total synthesis of the proposed structure 1-A of (+)-tolyporphin A O,O-diacetate (X=Ac). Comparison of the spectroscopic data demonstrated that synthetic tolyporphin O,O-diacetate did not match the O,O-diacetate prepared from natural (+)-tolyporphin A (X=H), calling for a structural revision of this class of natural products. On the basis of a series of NMR experiments including synthetic intermediates, the structure of tolyporphin A is concluded to be 1-B, in which the configurations of quaternary centers C7 and C17 are opposite to those in the originally proposed structure.

Keywords: NMR spectroscopy; Natural products; Porphyrinoids; Structure elucidation.