72586-64-2Relevant articles and documents
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
, p. 457 - 462 (2018)
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.
SYNTHESIS OF THE POTENT IMMUNOSUPPRESSANT AGENTS DALESCONOL A AND B
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, (2011/09/19)
This invention relates to compounds having the structure: wherein bonds α, β, γ, δ, ω, η, χ, ε, κ, and μ are each present or absent, and R1-R18 are various substituents described herein.
