An Unexpected Formation of Spiro Isoxazoline-Dihydrofurane Compounds from Substituted Ketofurfuryl Alcohols.

Oximation of substituted ketofurfuryl alcohols in the presence of hydroxylamine hydrochloride and pyridine in ethanol as solvent led to a new class of spiro derivatives presenting a 7-methylene-1,6-dioxa-2-azaspiro [4.4] nona-2,8-diene skeleton along with, in some cases, the predictable oxime. The structures of such spiro compounds were determined by 2D NMR spectroscopy.

Reaction of Glyconitriles with Organometallic Reagents: Access to Acyl β-C-Glycosides.

A new strategy for the synthesis of acyl β-C-glycosides is described. The reactivity of glyconitriles toward organometallic reagents such as organomagnesium or organolithium derivatives was studied, affording acyl β-C-glycosides in moderate to good yields. In this study, glycal formation was efficiently prevented by deprotonating the hydroxyl group in position 2 of the glyconitriles during the process.

3-fluoro- and 3,3-difluoro-3,4-dideoxy-KRN7000 analogues as new potent immunostimulator agents: total synthesis and biological evaluation in human invariant natural killer T cells and mice.

We propose here the synthesis and biological evaluation of 3,4-dideoxy-GalCer derivatives. The absence of the 3- and 4-hydroxyls on the sphingoid base is combined with the introduction of mono or difluoro substituent at C3 (analogues 8 and 9, respectively) to evaluate their effect on the stability of the ternary CD1d/GalCer/TCR complex which strongly modulate the immune responses. Biological evaluations were performed in vitro on human cells and in vivo in mice and results discussed with support of modeling studies.

Synthesis and glycosidase inhibitory activity of 1-amino-3,6-anhydro-1-deoxy-D-sorbitol derivatives.

3,6-Anhydro-1-(aryl or alkylamino)-1-deoxy-D-sorbitol derivatives have been prepared in four steps from isosorbide, a by-product from the starch industry. The inhibitory activities of these new compounds have been evaluated towards 13 glycosidases. A first lead-compound was identified, which inhibited beta-N-acetylglucosaminidase from bovine kidney (82% inhibition at 1mM).

Polymer-supported catalysts: enantioselective hydrogenation and hydrogen transfer reduction.

Different types of heterogenized catalysts were involved in asymmetric reactions. Hydrogen transfer reduction was performed with amino alcohols derived from poly((S)-(GMA-co-EGDMA or DVB)) and hydrogenation with BINAP grafted onto PEG or copolymerized with isocyanates as ligands. Attempts of catalysts recycling are reported.