Total Synthesis of Cyclic Diterpene Tonantzitlolone Based on a Highly Stereoselective Substrate-Controlled Aldol Reaction and Ring-Closing Metathesis

• Published in: Chemistry : a European journal Vol. 12; no. 34; pp. 8719 - 8734
• Main Authors: Jasper, Christian, Adibekian, Alexander, Busch, Torsten, Quitschalle, Monika, Wittenberg, Rüdiger, Kirschning, Andreas
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 24-11-2006; WILEY‐VCH Verlag
• Subjects: aldol reactions; Cyclization; Diterpenes - chemical synthesis; Macrocyclic Compounds - chemical synthesis; Models, Chemical; natural products; ring-closing metathesis; Stereoisomerism; terpenes; total synthesis
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200600082

The total synthesis of the cyclic diterpene ent‐tonantzitlolone (ent‐1) is presented. Key steps for assembling the macrocyclic core structure of 1 are a highly selective aldol reaction and an E selective ring‐closing metathesis reaction. A detailed investigation of these two steps and the final transformations towards the completion of the synthesis is disclosed.
Stereocontrol is a never‐ending issue in natural product synthesis! It is strongly addressed for an anti‐Felkin‐aldol reaction and E‐selective ring‐closing metathesis during the total synthesis of the antitumor active diterpene tonantzitlolone (see scheme).