Vilsmeier-haack reactoin of glycals-a short route to C-2-formyl glycals☆
TL;DR: A short and straightforward route has been accomplished for the synthesis of C-2-formyl glycals by a Vilsmeier-Haack reaction of glycals.
About: This article is published in Tetrahedron Letters.The article was published on 1991-07-29. It has received 52 citations till now. The article focuses on the topics: Glycal.
Citations
More filters
TL;DR: In this paper, the synthesis of tri-O-benzyl-2-C-acetoxymethyl glycals and subsequent Ferrier rearangement to give 2C-methylene glycosides is described.
Abstract: Syntheis of tri-O-benzyl-2-C-acetoxymethylglycals and subsequent Ferrier rearangement to give 2-C-methylene glycosides is described.
24 citations
TL;DR: Recent developments in the synthesis and applications of 2-C-formyl-glycals, the versatile chiral intermediates, are summarized in this review.
22 citations
TL;DR: A general N-heterocyclic carbene (NHC)-promoted annulation reaction of allenals with chalcones affording polysubstituted pyranyl aldehydes has been developed.
21 citations
TL;DR: In this article, O-tert-butyldimethylsilylated (O-TBDMS) or O-triethyl silylated alcohols were converted in one step to their corresponding formates under Vilsmeier-Haack conditions ( POCl 3 DMF ).
21 citations
TL;DR: A facile and efficient one-pot synthesis of acyclic polyols fused with pyrazolo[1,5-a]pyrimidines and 1,2,4-triazolo[3,aminopyrazoles] with regioselectivity was achieved through the condensation of 2-C-formyl glycals with 3-aminopy Razoles in excellent yields under the microwave irradiation.
Abstract: A facile and efficient one-pot synthesis of acyclic polyols fused with pyrazolo[1,5-a]pyrimidines and 1,2,4-triazolo[1,5-a]pyrimidines as novel carbohybrids with regioselectivity was achieved through the condensation of 2-C-formyl glycals with 3-aminopyrazoles and 3-amino-1,2,4-triazoles in excellent yields under the microwave irradiation.
20 citations
References
More filters
146 citations
TL;DR: The Tetrasaccharid Lycotetraose, das im Tomatin with Tomatidin verknupft ist, lies sich strukturell aufklaren, indem 1. Tomatin, 2. Glykosid (β 1-Tomatin) and 3. das xylosefreie Trisaccharide Triscarid (Lycotriose), letzteres nach katalytischer Hydrierung zum Lycotriit, with Methyljodid and Silber
Abstract: Das Tetrasaccharid Lycotetraose, das im Tomatin mit Tomatidin verknupft ist, lies sich strukturell aufklaren, indem 1. Tomatin, 2. das daraus durch Abspaltung von D-Xylose gewonnene Glykosid (β1-Tomatin) und 3. das xylosefreie Trisaccharid (Lycotriose), letzteres nach katalytischer Hydrierung zum Lycotriit, mit Methyljodid und Silberoxyd in Dimethylformamid permethyliert wurden. Aus den Spaltstucken der permethylierten Verbindungen, die kristallisiert erhalten wurden, ergibt sich fur die Lycotetraose die verzweigte Konstitution einer β-D-Glucopyranosyl(1 2Glucose)-β-D-xylopyranosyl(1 3Glucose)-β-D-glucopyranosyl(1 4Galaktose)-α-D-galaktopyranose und damit fur das Tomatin die Formel I. Auch aus Demissin last sich, unter Abspaltung von D-Xylose und des Aglykons, kristallisierte Lycotriose gewinnen.
110 citations
TL;DR: Three fluoro-substituted unsaturated sugars have been synthesized by transformations within the D-glucal and ethyl 2,3-dideoxy-α-D-erythro-hex-2-enopyranoside series.
Abstract: Three fluoro-substituted unsaturated sugars have been synthesized by transformations within the D-glucal and ethyl 2,3-dideoxy-α-D-erythro-hex-2-enopyranoside series. A number of the intermediate unsaturated sugars not previously described have been characterized. The advantages of the t-butyldimethylsilyl blocking group in such syntheses are described.
71 citations
TL;DR: The palladium-catalyzed couplings of the protected 1-(tributylstannyl)-D-glucal 1 and substituted aryl bromides provide the corresponding C-arylglucals and a dimer as mentioned in this paper.
Abstract: The palladium-catalyzed couplings of the protected 1-(tributylstannyl)-D-glucal 1 and substituted aryl bromides provide the corresponding C-arylglucals and a dimer
70 citations
TL;DR: In this article, it was shown that triacetyl glucal can be converted to 6-O-triphenylmethyl ether or 6 O-benzoyl ester to promote solubility in chloroform, and the derivatives are oxidized in that solvent in 12 h or less.
Abstract: Whereas the pseudo-axial 3-hydroxyl group of allal derivatives is known to be inert to manganese dioxide oxidation, the equatorial counterpart in glucal derivatives is shown to be readily oxidized. Thus glucal is converted to the 6-O-triphenylmethyl ether or 6-O-benzoyl ester to promote solubility in chloroform, and the derivatives are oxidized in that solvent in 12 h or less.Acetonation of glucal is readily accomplished in 45 min using 2,2-dimethoxypropane and p-toluenesulfonic acid in dimethylformamide; the product may be oxidized directly either with manganese dioxide or dipyridine chromium oxide. Thus it is possible to obtain 1–3-g quantities of the crystalline acetonated enone from triacetyl glucal (via deacetylation, acetonation, and oxidation) in 3–4 h.If the acetonation medium stands for 2 h methyl 2,3-dideoxy-4,6-O-isopropylidene-α-D-erythro-hex-2-enopyranoside is obtained. The mechanism of its formation in the reaction medium is discussed.
64 citations