Total Synthesis of Arylnaphthalene Lactone Natural Products via Hauser-Kraus Annulation and Suzuki-Miyaura Cross-Coupling Reaction

Abstract

In this study, a novel and simple method for the preparation of various arylnaphthalene lactone natural products was developed and used to synthesize diphyllin (10), justicidin A (12), cilinaphthalide B (13), taiwanin E (15), chinensinaphthol (16), taiwanin E methyl ether (17), chinensinaphthol methyl ether (18), justicidin C (21) and justicidin D (22). The syntheses proceeded via Hauser-Kraus annulation of cyanophthalides (7a and 7b) and Suzuki-Miyaura crosscoupling of arylnaphthalene lactones having a sulfonate group (9, 14, 19, and 20) with the corresponding potassium aryltrifluoroborates.