Biomimetic synthesis of dimeric metabolite acremine G via a highly regioselective and stereoselective Diels-Alder reaction.

The dimeric metabolite acremine G was synthesized featuring a highly regioselective and stereoselective Diels-Alder reaction between a TBS-protected hydroquinone diene and a structurally related alkenyl quinone. The major endo [4 + 2] adduct slowly transforms to acremine G by the atmospheric air under the deprotection conditions (in situ generated HF).