Synthese von β‐D‐Glucopyranosiden einiger hydroxylierter Vitamin‐D‐Verbindungen

Abstract

Synthesis of P-o-Glucopyranosides of some Hydroxylated Vitamin-D Compounds SummaryCholesta-5,7-diene-l a, 3P-diol (la) was glycosylated with 'a-acetobromoglucose' (2) as well as with 'a-acetobromocellobiose' (4) to yield the 3-(glycosides) l b and lc, respectively. Irradiation of these products with UV light followed by thermal isomerization led to the corresponding vitamin-D derivatives 3a and 3c. Direct glucosylation of vitamin D, ( 3 0 and vitamin D, (5a) with 2 gave the derivatives 3g and 5b, respectively. With 25-hydroxycholecalciferol ( = calcidiol; 6 a) as substrate, besides the 3-(glucoside) 6b small amounts of the C(25)-analog 6 c were formed. The reaction of la,25-dihydroxycholecalciferol ( = calcitriol; 6e) with 2 furnished the 3-and the 1-(glucoside) (6f and 6g, respectively) as the major components and the C(25)-analog 6h in minor quantity. From the acetylated 3-(glucosides) 3 a, 3g, 5 b, 6 b, and 6f, the free glucopyranosides 3b, 3h, 5c, 6d, and 6 4 respectively, were prepared as well as the free glucopyranosyl-glucopyranoside 3d from the acetylated disaccharide 3c.

Characterization and Quantitation of Steryl Glycosides in Solanum melongena

“…In general, diethyl ether was used as the solvent for the coupling reaction to give approximately 20–35% product. To increase the initially negligible yields to about 5% for steryl cellobiosides (steryl-Cellos), 40% dichloromethane had to be added to the solvent, as proposed by Fürst et al Common reaction byproducts, such as α-glucosides or orthoesters, were separated by silica-gel column chromatography from the crude products to yield the pure peracetylated β-glycosides. , The β-glycosidic character of these intermediates was proven by 1 H NMR analyses to give a characteristic doublet for the anomeric protons H-1′ ( J = 7.6–7.9 Hz). Final deacetylation of the sugar moieties was achieved with methanolic KOH in an almost quantitative manner.…”

“…The NMR-data is found in the Supporting Information (Tables SI 4 and SI 5). Interestingly, 7-DHC-Glc has been synthesized before, but no characterization was given, whereas D 3 -Glc was fully characterized, but it was synthesized by irradiation from 7-DHC-Glc. ,, Although the NMR-data for the attached glucose was virtually identical for all three structures, the sterol backbone showed specific differences. 7-DHC-Glc, in contrast to Chol-Glc, displayed carbon resonances for the additional double bond at 117.7 and 140.9 ppm for C-7 and C-8, respectively.…”

“…Cholesteryl β- d -glucopyranoside (Chol-Glc), steryl β- d -glucopyranosides (β-sitosteryl-Glc, stigmasteryl-Glc, and campesteryl-Glc), steryl β- d -galactopyranosides (β-sitosteryl-Gal, stigmasteryl-Gal, and campesteryl-Gal), steryl β- d -glucopyranosyl-(1→4)-β- d -glucopyranosides (steryl β- d -cellobiosides: β-sitosteryl-Cello, stigmasteryl-Cello, and campesteryl-Cello), 7-dehydrocholesteryl β- d -glucopyranoside (7-DHC-Glc), and cholecalciferyl β- d -glucopyranoside (D 3 -Glc) were synthesized using the Koenigs–Knorr reaction. , …”

A Vitamin D3 Steroid Hormone in the Calcinogenic Grass Trisetum flavescens

“…Recently, Fürst et al [29] synthesized for the first time ß-D-glucopyranosides of some hydroxylated vitamin D metabolites. We compared the bioactivity of T. flavescens with two la(O H )D 3 glucosides and with the three possible l,25(O H )2D3 glucosides.…”

Steroids: reactions and partial syntheses

“…The P-D-glucopyranosides of vitamins D2 and D3 and of the 1 -hydroxy-, 25-hydroxy-, and 1,25-dihydroxy-derivatives of the latter compound have been described. 148 Syntheses of a number of precursors of the metabolites of the vitamins D are described in Section 2.1.…”