Palladium-mediated arylation of acetylated enones derived from glycals. 4. Synthesis of aryl-2-deoxy-.beta.-D-C-glycopyranosides
摘要:
The palladium-mediated arylation of the peracetylated glycal-derived enones 1, 2, and 3 afforded mixtures of C-glycosides containing an arylated enone (1a, 2a, or 3a) and an arylated ketone (1b, 2b, or 3b). A rationale for the formation of these compounds is given. Reduction of the arylated enones proceeds in a stereospecific manner, thus affording aryl 2-deoxy-beta-D-C-glycopyranosides in high yield.
excellent yields under mild conditions by the condensation of acetylated glycals with purine or pyrimidine derivatives in the presence of trityl perchlorate. The synthesis of (α- and β-hex-2-enopyranosyl-4-ulose)theophylline nucleosides labelled at position 3′ with deuterium is described.
Synthesis of N-benzoyl-L-ristosamine and intermediates used in its
申请人:Purdue University
公开号:US04298726A1
公开(公告)日:1981-11-03
A process for synthesizing N-benzoyl-L-ristosamine is disclosed. Intermediates useful for synthesizing N-benzoyl-L-ristosamine, and processes for preparing such intermediates, are also disclosed.
Stereoselective Syntheses of 2-Deoxy-β-<i>C</i>-arabino- and ribopyranosides: 2-Deoxy-β-arabino- and ribopyranosyl Cyanides
作者:Kuniaki Tatsuta、Jun Hayakawa、Yukio Tatsuzawa
DOI:10.1246/bcsj.62.490
日期:1989.2
2-Deoxy-β-arabino- and ribopyranosyl cyanides, which should be suitable for the syntheses of biologically active products, were stereoselectively prepared from the reaction of the enones, 1,5-anhydro-2-deoxy-erythro-hex-1-en-3-ulose derivatives, with acetone cyanohydrin, followed by the stereoselective reduction of the producing ketones with NaBH4–CeCl3·7H2O and l-Selectride, respectively.
Oxidation of Fully Protected Glycals by Hypervalent Iodine Reagents
作者:Andreas Kirschning
DOI:10.1021/jo00110a028
日期:1995.3
A new application of organoiodine(III) is presented. Fully protected glycals are directly converted into 2,3-dihydro-4H-pyran-4-ones by [hydroxy(tosyloxy)iodo]benzene (PhI(OH)OTs, 1). The detailed study reveals that this conversion is independent of the relative stereochemistry as well as the nature of protection on the pyran ring. 3-O-Silyl groups are most smoothly converted into the keto group giving 2,3-dihydro-4H-pyran-4-ones in yields up to 74%. In contrast, 4,6-di-O-acetyl-3-deoxyglucal (19) affords the rearranged oxidation product 32. Both observations can be reconciled by the proposed mechanism.
The total synthesis of avermectin A1a
作者:Samuel J. Danishefsky、David M. Armistead、Francine E. Wincott、Harold G. Selnick、Randall Hungate