Expeditious construction of the DEF ring system of thiersinine B.
Construction of a DEF ring model of thiersinine B has been achieved from a Wieland-Miescher ketone derivative by a five-step sequence featuring a one-pot regioselective α-allylation of the starting α,β-unsaturated ketone via the Claisen rearrangement and a double dihydroxylation of a dienone intermediate.