Total Synthesis of the Natural Enantiomer of (â)-Lepadiformine and Determination of Its Absolute Stereochemistry This work was supported in part by a Grant for Private Universities provided by the Ministry of Education, Sports, and Culture of Japan and the Promotion and Mutual Aid Corporation for Private Schools of Japan. We are grateful to Professor J. F. Biard for a sample of natural lepadiformine.
Total Synthesis of the Tricyclic Marine Alkaloids (−)-Lepadiformine, (+)-Cylindricine C, and (−)-Fasicularin via a Common Intermediate Formed by Formic Acid-Induced Intramolecular Conjugate Azaspirocyclization
作者:Hideki Abe、Sakae Aoyagi、Chihiro Kibayashi
DOI:10.1021/ja040213e
日期:2005.2.1
A very short and efficient enantioselective total synthesis of the tricyclic marine alkaloids (-)-lepadiformine (3), (+)-cylindricine C (1c), and (-)-fasicularin (4) has been developed utilizing the formyloxy 1-azaspiro[4.5]decane 5 as a common intermediate. The key strategic element for the synthesis was the formic acid-induced intramolecular conjugate azaspirocyclization, which proved to be a highly