119070-22-3Relevant academic research and scientific papers
Reagent-Controlled Stereoselective Glycosylation
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Paragraph 0042, (2015/02/19)
Provided are methods for the efficient stereoselective formation of glycosidic bonds, without recourse to prosthetic or directing groups.
Development of an effective chiral auxiliary for hydroxyalkyl radicals
Garner, Philip,Anderson, James T.,Cox, Philip B.,Klippenstein, Stephen J.,Leslie, Ray,Scardovi, Noemi
, p. 6195 - 6209 (2007/10/03)
The development of an effective chiral auxiliary for hydroxyalkyl radicals is delineated. Both the 2-tetrahydropyranyl (THP) and tri-O-benzyl-2-deoxy-α-D-glucopyranosyl (GLU) auxiliaries resulted in diastereoselective radical additions to methyl acrylate at -78°C (ds = 6/1 and 11/1, respectively). The developing stereochemistry at the radical center was completely under auxiliary control. Correlation experiments showed that the D-GLU auxiliary led to attack on the radical Si-face. The selectivity of these radical additions dropped-off considerably when the more reactive 2-nitropropene trap was employed. Computational studies suggested that the observed facial selectivity was due primarily to entropic factors in the transition state but that a smaller temperature-dependent enthalpic contribution was also involved. It was hypothesized that incorporation of a quaternary center at C-6 (THP numbering) would restore the facial selectivity with more reactive radical traps by restricting the orientations available to the incoming alkene. In the event, the trans-6-tert-butyltetrahydropyranyl (tBu-THP) auxiliary resulted in very good diastereoselection with 2-nitropropene (ds = 35/1 at -78°C, 15/1 at 0°C, and 8/1 at RT) as did the tri-O-benzyl-6,6-dimethyl-2-α-D-deoxyglucopyranosyl (diMe-GLU) auxiliary during additions to ethyl α-trifluoroacetoxyacrylate (ds = 10/1 at 0°C). A protocol for recovery of the sugar-derived chiral auxiliaries was also established. This work sets the stage for the development of a novel approach to 1, 3, 5...(2n + 1) polyols based on iterative radical homologation as well as the application of these pyranosidic auxiliaries to other synthetically important reactions.
Diastereoselective Free-radical Reactions. Part 1. Preparation of 2-Deoxy-β-glycosides by Synthesis and Reductive Decarboxylation of 3-Deoxyulosonic Acid Glycosides
Crich, David,Ritchie, Timothy J.
, p. 945 - 954 (2007/10/02)
A general procedure for the synthesis of 2-deoxy-β-D-glycosides involving the preparation of 3-deoxyulosonic acid glycosides from glycals and their reductive decarboxylation is described.
Preparation and reductive lithiation of 2-deoxy-D-glucopyranosyl phenylsulfones: A highly stereoselective route to C-glycosides
Beau,Sinay
, p. 6185 - 6188 (2007/10/02)
2-Deoxy-D-glucopyranosyl phenylsulfones 3a-c have been synthesized in 75-83% yield from commercial tri-O-acetyl-D-glucal 1. Their reductive desulfonylation by lithium naphthalenide and reaction of the intermediate glycosyl-lithium 5 with aldehydes leads t
