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A Short Synthesis of Natural Isocoumarin Glucoside Delphoside
Author(s) -
Aamer Saeed
Publication year - 2005
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.200590762
Subject(s) - chemistry , isocoumarin , boron trifluoride , demethylation , regioselectivity , glucoside , potassium carbonate , isocoumarins , organic chemistry , amine gas treating , yield (engineering) , chloride , glycosylation , medicinal chemistry , catalysis , biochemistry , medicine , gene expression , alternative medicine , materials science , pathology , metallurgy , dna methylation , gene
A simple synthesis of delphoside, 3‐methyl‐6‐hydroxy‐8‐ O ‐β‐ D ‐glucopyranosyloxy isocoumarin ( 1 ), isolated from Delphinium spp. is described. 3,5‐Dimethoxyhomophthalic anhydride ( 2 ) on treatment with acetyl chloride in the presence of 1,1,3,3‐tetramethylguanidine (TMG) and triethyl amine afforded the 6,8‐dimethoxy‐3‐methylisocoumarin ( 3 ). Regioselective demethylation of the latter furnished 8‐hydroxy‐6‐methoxy‐3‐methylisocoumarin ( 4 ). Glycosylation with O ‐(2,3,4,6‐tetra‐ O ‐acetyl‐ D ‐glucopyranosyl)trichloroacetimidate in presence of catalytic amount of boron trifluoride etherate followed by deacetylation using 5% potassium carbonate afforded 3‐methyl‐6‐methoxy‐8‐ O ‐β‐ D ‐glucopyranosyloxyisocoumarin ( 6 ) that was finally demethylated to yield delphoside 1 .