title: Simple Synthesis of Sakuranetin and Selinone via a Common Intermediate, Utilizing Complementary Regioselectivity in the Deacetylation of Naringenin Triacetate.
abstract: Sakuranetin and selinone were successfully synthesized utilizing the regioselective deacetylation of naringenin triacetate. Deacetylation of the latter at C-7 with imidazole in 1,4-dioxane at 40°C furnished the corresponding diacetate in 80% yield. Methylation of the obtained free hydroxy group and subsequent removal of the remaining two acetyl groups gave sakuranetin, which was previously isolated as a phytoalexin against rice blast disease fungus, Pyricularia oryzae, in 71% overall yield. The same intermediate, naringenin triacetate, was subjected to transesterification with 2-propanol in tetrahydrofuran, catalyzed by Candida antarctica lipase B. A contrasting regioselective preference for C-4' deacetylation was observed, giving an isomeric diacetate in 82% yield. Prenylation of the free hydroxy group under Mitsunobu conditions and subsequent deprotection furnished selinone, which was previously isolated from Monotes engleri and exhibits antifungal activity against Candida albicans, in 55% overall yield.
authors.affiliation: Department of Pharmaceutical Sciences, Keio University.
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Kengo
authors.initials: K
authors.lastname: Hanaya
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Shoji
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sugai
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000107:Acetylation; D000935:Antifungal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001203:Ascomycota / Q000187:drug effects; D002176:Candida albicans / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D044950:Flavanones / Q000737:chemistry*; D005419:Flavonoids / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D000094162:Phytoalexins
chemical_list: D000085:Acetates; D000935:Antifungal Agents; D044950:Flavanones; D005419:Flavonoids; C099724:sakuranetin; D000094162:Phytoalexins; C000613666:selinone; C005273:naringenin