Stereoselective synthesis of thiaerythrinanes based on an α-amidoalkylation/RCM approach

Parham cyclisation–intermolecular α-amidoalkylation and nucleophilic addition–intramolecular α-amidoalkylation sequences constitute diastereocomplementary routes to 1,10b-cis and trans thiazolo[4,3-a]isoquinolinones. These thiazolidinediones, that incorporate allyl groups at C-1 and C-10b, are efficient precursors of thiaerythrinanes by ring-closing metathesis reactions.