ISSN:
1434-193X
Keywords:
Ozonolysis
;
Natural products
;
Iridoid glucosides
;
Scutellarioside I
;
Antirrhinoside
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Scutellaria subvelutina was found to be an excellent source of the catalpol ester scutellarioside I (3) and this was chemically converted into 5,7-dideoxycynanchoside. The partially protected iridoid glucosides, 8,10:4′,6′-di-O-isopropylidene-5,7-dideoxycynanchoside (6) and 6,2′,3′,6′-tetra-O-benzoylantirrhinoside (10), as well as the fully protected 5,6-O- isopropylidene-2′,3′,4′,6′-tetra-O-acetylantirrhinoside (8a) were subjected to ozonolysis with reductive work-up using sodium tetrahydridoborate. Using a large excess of reductant, the reaction mixtures from 6 and 8a were reduced completely to give the respective polysubstituted cyclopentanols, while reduction of the ozonolysis product from 10 could be stopped at the hemiacetal 11 by employing a smaller amount of reductant.
Type of Medium:
Electronic Resource
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