A Novel Stereospecific Synthesis of Glycosyl Cyanides from 1,2-O-Sulfinyl Derivatives

Abstract

[reaction: see text] An efficient synthesis of 1,2-trans-glycosyl cyanides via 1,2-O-sulfinyl monosaccharides is described. Such S(N)2-type displacements at the anomeric center are stereospecific and are best performed with sodium cyanide in the presence of ytterbium triflate. Significantly, the resulting 1,2-trans-glycosyl cyanides have a free hydroxyl group at C-2 ready for further modification.

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

“…. 20 To a solution of compound 5a (12.9 g, 25.7 mmol) in dry diethyl ether (16.0 mL) was added a saturated solution of ammonia in MeOH (193 mL) at rt. The reaction mixture was stirred for 24 h (until TLC indicated complete conversion).…”

1,2-Cyclic sulfite and sulfate furanoside diesters: improved syntheses and stability

“…15 However Beaupere reported that such cyclic sulfites could be obtained for the pyranose form of arabinose. 8 In order to establish whether direct access to cyclic sulfites and sulfates species could be formed from 1,2-and 3,5-deprotected sugars (Scheme 1), the reactions of a series of sugar-diols (Table 1, 1-4) and bases with thionyl chloride were investigated.…”

“…Similarly, cyclic sulfite/sulfate esters have had limited applications due to problems associated with their syntheses 4,6,7 (e.g., difficulties in controlling cyclisation vs chlorination), as well as their variable reactivity towards nucleophiles. 8,9 For example, there are currently only two reported procedures used to prepare 1,2-cyclic sulfites from 1,2-diols. These involve thionyl chloride or N,N 0 -thionyl diimidazole in pyridine under anhydrous and temperature controlled conditions.…”

“…These involve thionyl chloride or N,N 0 -thionyl diimidazole in pyridine under anhydrous and temperature controlled conditions. 8,10 Similarly, this chemistry is not applicable to cyclic sulfates which are prepared from the cyclic sulfite precursors, via oxidation with ruthenium tetroxide, thus limiting their potential usage especially within an industrial setting. 5 These issues are further exacerbated in the case of partially protected sugar 1,2-diols which do not behave as standard diols, as the stereochemistry of anomeric position (alpha and beta configuration at C-1 of the sugar) controls the sulfite/sulfate formation, reactivity and stability, especially towards water.…”

A Novel Approach to the Synthesis of N‐Substituted 1‐C‐Aminomethyl Glycofuranosides.

“…Syntheses of 1-C-aminomethyl glycosides so far described rely on the introduction of a CH 2 NH 2 equivalent at the anomeric position: (a) as CH 3 NO 2 via nucleophilic aldol reaction, 7 (b) by reducing the corresponding glyco-syl cyanide 8 or, (c) by degradation of a C-vinyl glycoside and subsequent formation of the azidomethyl intermediate. 3b Alternatively, rearrangement involving 5-exo S N 2opening of a terminal aziridine ring, and transformation of a primary hydroxyl function into the corresponding azide gave access to the 2,5-anhydro derivatives 3 4 and 4, 9 respectively.…”