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The First Total Synthesis of Cytopiloyne, an Anti‐Diabetic, Polyacetylenic Glucoside
Author(s) -
Kumar Chidambaram Ramesh,
Tsai ChiHui,
Chao YuSheng,
Lee JinqChyi
Publication year - 2011
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201100986
Subject(s) - alkyne , total synthesis , moiety , chemistry , glycosylation , stereochemistry , stereoselectivity , glycoside , glucoside , diastereomer , convergent synthesis , natural product , coupling reaction , sequence (biology) , combinatorial chemistry , catalysis , organic chemistry , medicine , biochemistry , alternative medicine , pathology
The first total synthesis of cytopiloyne 1 , a novel bioactive polyacetylenic glucoside isolated from the extract of Bidens pilosa , is described. The structure of cytopiloyne was determined to be 2‐β‐ D ‐glucopyranosyloxy‐1‐hydroxytrideca‐5,7,9,11‐tetrayne by using various spectroscopic methods, but the chirality of the polyyne moiety was unknown. Herein, the convergent synthesis of two diastereomers of cytopiloyne by starting from commercially available 4‐(2‐hydroxyethyl)‐2,2‐dimethyl‐1,3‐diozolane is described. The synthetic sequence involved two key steps: stereoselective glycosylation of the glucosyl trichloroacetimidate with 1‐[(4‐methoxybenzyl)oxy]hex‐5‐yn‐2‐ol to give the desired β‐glycoside and the construction of the glucosyl tetrayne skeleton by using a palladium/silver‐catalyzed cross‐coupling reaction to form the alkyne–alkyne bond, the first such use of this reaction. Comparison between the observed and published characterization data showed the 2 R isomer to be the natural product cytopiloyne.