Synthesis of Chiral 3E,5E-Octadiene-1,2R,7R,8-tetraol Frameworks by Means of Palladium(II)-Promoted Hetero-Claisen Rearrangement: Mechanistic Aspect.

Abstract A plausible mechanism has been proposed for the exclusive formation of symmetrical dienediol such as 1,6-bis(acetoxy)-2,4-diene in palladium(II)-promoted [3,3]sigmatropic rearrangement of 3,4-bis(acetoxy)-1,5-diene system. This mechanism referred to as migration-induced intramolecular dioxanium ion switching (MIDIS) process can reasonably explain why the vicinal acetoxy groups move from 3,4-position not to 5,6- but two-directionally to 1,6-position.