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Communication | Regular issue | Vol 19, No. 1, 1982, pp.31-36
Published online, 1st January, 1970
DOI: 10.3987/R-1982-01-0031
Ring D Inversion of Protoberberine Alkaloids. Conversion of Berberine into Non-naturally Occurring 11,12-Oxygenated Protoberberines

Miyoji Hanaoka, Mitsuru Inoue, Misao Takahashi, and Shingo Yasuda

*Faculty of Pharmaceutical Scicences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan


Three methods were developed for the transformation of a naturally occurring 9,l0-oxygenated protoberberine, berberine into a non-naturally occurring 11,12-oxygenated protoberberine through ring D inversion via a corresponding spirobenzylisoquinoline.