Synthesis and Solution Conformational Analysis of 2,3-Anhydro-3-C-[(1R)-2,6-anhydro-1-deoxy-1-fluoro-d-glycero-d-gulo- heptitol-1-C-yl]-β-d-gulo-furanose:  First Example of a Monofluoromethylene-Linked C-Disaccharide

Abstract

Condensation of 2,3,4,6-tetra-O-benzyl-beta-D-glucopyranosylcarbaldehyde with isolevoglucosenone induced by Et(2)AlI, followed by epoxidation, gave an aldol that was fluorinated into a monofluoromethylene C-glucopyranoside that was converted into the title C-disaccharide 1. Its conformational behavior in water has been studied by using a combination of NMR spectroscopy (J and NOE data) and molecular mechanics calculations.

Constrained 3,6‐Anhydro‐Heptosides: Synthesis by a DAST‐Induced Debenzylative Reaction, and Reactivity Profile

“…[8] A small amount of by-product 11 (11 %), fluorinated at C-1, was isolated after purification by flash chromatography. [8] A small amount of by-product 11 (11 %), fluorinated at C-1, was isolated after purification by flash chromatography.…”

“…20 CH arom ), 99.8 (C-1), 78.9 (d, J C,P = 7.7 Hz, C-6), 77.0 (C-4), 75.1 (C-3), 73.4 (C-5), 72.3 (C-2), 72.2 (CH 2 Bn ), 71.7 (CH 2 Bn ), 69.6 (d, J C,P = 2.9 Hz, CH 2 Bn ), 69.5 (d, J C,P = 3. 8 …”

Fluoro-C-glycosides and fluoro-carbasugars, hydrolytically stable and synthetically challenging glycomimetics

“…Vogel and Jime ´nez-Barbero et al reported in 2001 the preparation and conformational analysis of a CFH-linked disaccharide. 17 The low temperature, DAST-mediated nucleophilic fluorination of the corresponding alcohol 22 afforded 23 stereoselectively in 73% yield (Scheme 10). In contrast, the difluorination of glycosylarylketones a-24 and b-24 required a more active reagent, higher concentrations, higher temperatures and longer reaction times.…”

Synthesis of C-linked analogues of β-d-galactopyranosyl-(1→3)-d-galactopyranosides and of β-d-galactopyranosyl-(1→3)-d-galactal

“…We had applied the Oshima-Nozaki coupling reaction of enones and aldehydes 13 to a 2,3,4,6-Otetrabenzyl-b-D D-glucopyranosylcarbaldehyde and isolevoglucosenone 4 14 and obtained 2,3-anhydro-3-C-[(lS)-2,6-anhydro-D D-glycero-D D-gulo-heptitol-l-C-yl]-b-D D-gulopyranose 15 and a fluorinated derivative. 16 We will show now that 2,3,4,6-O-tetrabenzyl-5a and 2,3,4,6-O-tetra [(tertbutyl)dimethylsilyl]-b-D D-galactopyranosylcarbaldehyde 5b 17,18 can be condensed with isolevoglucosenone 4 (Scheme 1) to produce enones 6a and 6b, respectively (Baylis-Hillmann type of products) which can be readily converted into C-linked analogues of b-D D-galactopyranosyl-(1!3)-D D-galactal derivatives 3a-3c. The carbon linker is a hydroxymethylene group in 3a and 3b, and a methylene group in 3c.…”