First Concise Total Syntheses of Biologically Interesting Nicolaioidesin C, Crinatusin C1, and Crinatusin C2

The efficient and concise total syntheses of naturally occurring dihydrochalcone nicolaioidesin C, crinatusin C1, and crinatusin C₂ have been achieved from the readily available 2,6-dihydroxy-4-methoxyacetophenone and 2,4-dihydroxy-6-methoxyacetophenone. The key steps in the synthetic strategy were aldol reaction and Diels-Alder reaction.