title: Synthesis of novel lupane triterpenoid-indazolone hybrids with oxime ester linkage.
abstract: An efficient protocol for the synthesis of novel lupane triterpenoid-indazolone hybrids with oxime ester linkage has been developed from naturally accessible precursor betulin. For the first time a series of betulonic acid-indazolone hybrids have been synthesized via an acylation of corresponding 6,7-dihydro-1H-indazol-4(5H)-one oximes with betulonic acid chloride. Diastereoselective reduction of the obtained betulonic acid conjugates with NaBH4resulted in a formation of betulinic acid-indazolone hybrids in excellent yields. The configuration of the key compounds has been fully established by X-ray and 2D NMR analysis.
authors: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Acad. Kuprevicha Str. 5/2, 220141 Minsk, Belarus.
authors: Tatyana S
authors: TS
authors: Khlebnicova
authors: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Acad. Kuprevicha Str. 5/2, 220141 Minsk, Belarus.
authors: Yuri A
authors: YA
authors: Piven
authors: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Acad. Kuprevicha Str. 5/2, 220141 Minsk, Belarus.
authors: Alexander V
authors: AV
authors: Baranovsky
authors: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Acad. Kuprevicha Str. 5/2, 220141 Minsk, Belarus.
authors: Fedor A
authors: FA
authors: Lakhvich
authors: Institute for Single Crystals, National Academy of Sciences of Ukraine, pr. Lenina 60, Kharkiv 61001, Ukraine.
authors: Svetlana V
authors: SV
authors: Shishkina
authors: Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, Riga LV-1048, Latvia.
authors: Daina
authors: D
authors: Zicāne
authors: Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, Riga LV-1048, Latvia.
authors: Zenta
authors: Z
authors: Tetere
authors: Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, Riga LV-1048, Latvia.
authors: Irisa
authors: I
authors: Rāviņa
authors: Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, Riga LV-1048, Latvia.
authors: Viktors
authors: V
authors: Kumpiņš
authors: Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, Riga LV-1048, Latvia.
authors: Inese
authors: I
authors: Rijkure
authors: Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, Riga LV-1048, Latvia.
authors: Inese
authors: I
authors: Mieriņa
authors: Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, Riga LV-1048, Latvia.
authors: Uldis
authors: U
authors: Peipiņš
authors: Institute of Technology of Organic Chemistry, Faculty of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, Riga LV-1048, Latvia. Electronic address: maris_turks@ktf.rtu.lv.
authors: Māris
authors: M
authors: Turks
mesh_terms: D015394:Molecular Structure; D009828:Oleanolic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D053978:Pentacyclic Triterpenes; D013329:Structure-Activity Relationship; D014315:Triterpenes / Q000737:chemistry*; D000094062:Betulinic Acid
chemical_list: D053978:Pentacyclic Triterpenes; D014315:Triterpenes; C118308:betulonic acid; C480546:lupane; D009828:Oleanolic Acid; D000094062:Betulinic Acid
keywords: Betulinic acid; Betulonic acid; Indazolone oximes; Triterpenoid-indazolone hybrids; X-ray structure