Total Synthesis of Diaporthichalasin by Using the IntramolecularDiels–Alder Reaction of an α,β‐Unsaturated γ‐Hydroxylactam in Aqueous Media

• DOI: 10.1002/asia.201201230
• Publication Date: 2013-03-28T17:45:18Z
• Authors: Nobuhiro Shionozaki; Naoki Iwamura; Ryo Tanaka; Kimiko Makino; Hiromi Uchiro
• Keywords: Cycloaddition Reaction; Lactams; Molecular Structure; Cyclization; Water; Cytochalasins; 01 natural sciences; 0104 chemical sciences

AbstractThe first total synthesis of diaporthichalasin has been successfully achieved and complete structure elucidation, including the absolute configuration, was also accomplished. The intramolecular Diels–Alder (IMDA) reaction between the diene side chain on the decalin skeleton and α,β‐unsaturated γ‐hydroxy‐γ‐lactam in aqueous media was effectively employed as the key step. From this synthetic study, we found that α,β‐unsaturated γ‐hydroxy‐γ‐lactam is an essential precursor for the construction of the diaporthichalasin‐type pentacyclic skeleton. This important finding strongly suggests that this route is involved in the biosynthetic pathway for diaporthichalasin.