Triterpene glycosides of ladyginia bucharica III. Structure of ladyginoside C
SummaryThe structure of ladyginoside C — a trioside of oleanolic acid — has been established. The carbohydrate chain is attached to the hydroxyl at C3 of the aglycone and consists of β-D-glucopyranosyl-(1→4)-α-L-arabopyranosyl-(1→4)-β-D-glucopyranuronic acid.
Steroid‐ und Triterpen‐glykoside. 3. Mitteilung. Glucoside von Oleanolsäure‐estern und glykosidische Bindung im Zuckerrüben‐Saponin
Durch Kondensation von Acetobrom-glucose (II) mit Oleanolsaure-methylester (la) wurde das Oleanolsaure-methylester-β, D-glucosid-tetraacetat (IV) und daraus das Oleanolsaure-methylester-β, D-glucosid (IVa) hergestellt; Oleanolsaure-benzhydrylester-β, D-glucosid-acetat (IVc) ist analog zuganglich.
Synthesis of 2,4-dideoxy-.beta.-D-erythro-hexopyranosyl nucleosides
The synthesis of 1-(2,4-dideoxy-β-D-erythro-hexopyranosyl)thymine (12) 1 was accomplished using two different synthetic routes. It was obtained starting either from 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose or from tri-O-acetyl-D-glucal. The other modified nucleosides, with either a cytosine, guanine, or adenine moiety, were synthesized using the second reaction scheme. Deoxygenation reactions were accomplished with the (2,4-dichlorophenoxy)thiocarbonyl derivatives generated in situ