89877-55-4Relevant academic research and scientific papers
Total Synthesis of Eleuthoside A; Application of Rh-Catalyzed Intramolecular Cyclization of Diazonaphthoquinone
Othman, Dina I. A.,Otsuka, Kota,Takahashi, Shuhei,Selim, Khalid B.,El-Sayed, Magda A.,Tantawy, Atif S.,Okauchi, Tatsuo,Kitamura, Mitsuru
supporting information, p. 457 - 462 (2018/02/23)
The first total synthesis of (±)-eleutherol and eleuthoside A, the natural cytotoxic substances extracted from medicinal Indonesian plant, is described. First, the synthesis of (±)-eleutherol has been accomplished in nine steps starting from bromo methoxy aldehyde with the aid of diazo-transfer chemistry approach. Second, a metal-catalyzed intramolecular cyclization reaction of the corresponding diazonaphthoquinone led to the desired eleuotherol, which served as a precursor to eleuthoside A. Then, several glycosidation routes, using different glucosyl donors, were experimented to reach effective O-glycosidation of eleutherol. The only successful strategy involved Koenigs-Knorr glycosidation using peracetyl glycosyl bromide in the presence of Ag 2 O and quinoline. This strategy furnished our desired acetylated glycoside of β-configuration, regioselectively. Finally, deacetylation and successive separation of diastereomers were conducted to give eleuthoside A.
