Concise Synthesis of Arylnaphthalene Lignans by Regioselective Intra­molecular Anionic Diels–Alder Reactions of 1,7-Diaryl-1,6-diynes

Total synthesis of phyllamycin A and C, justicidin B, and retrojusticidin B from simple arylalkynyl alcohols and (3,4-methylenedioxyphenyl)propynal was accomplished in 4–5 steps by employing an intramolecular anionic Diels–Alder reaction as the key step.