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

Controlling chlorination versus cyclosulfonation of cis-diols using ionic liquid solvents

“…DCM reactions have to be performed under anhydrous argon conditions whereas the IL-based reactions could be conducted in air due to the enhanced reagent stability of the reagents in ILs. 14 After 24 h, the reactions were sampled and analysed by 2 H NMR spectroscopy, the results of which are shown in Tables 1-4 ]. It should be noted, attempts to conduct fluorination reactions of diols using this in situ generated thionyl fluoride in this solvent were unsuccessful.…”

“…Following our success in stabilising thionyl-and sulfuryl-chlorides in ILs thus enabling formation of sulfite and sulfate derivatives of carbohydrates with much improved yields. 14,15 We report here the use of ILs to modulate chlorination versus sulfonation of a range of diols. 2 H NMR was used to monitor the reactions and demonstrates how the chemoselectivity and product distribution can be controlled by using IL solvents.…”

Reactivity of 1,2-cyclic sulfite xylosides towards nucleophiles

“…9 These syntheses were achieved using immobilised morpholine as co-reagent. A suitably protected diol was converted to the cyclic sulfite by reaction with thionyl chloride in the presence of immobilized morpholine.…”

“…Mechanism of oxazoline formation in ILs.mixture was filtered on a thin pad of silica and the resin rinsed with a large volume of dichloromethane. The filtrate was concentrated under reduced pressure to yield the expected compound (87%) as clear oil that crystallised with time and was stored at 4 C. Mixture of two diastereoisomers at the sulfur centre was obtained in a Hz, H-3a), 5.14 (d, 1H, J¼3 9. Hz, H-2a), 5.00 (dt, 1H, J¼3.8, 6.3 Hz, H-4b), 4.83 (d, 1H, J¼4 8.…”

Reactions of enantiopure cyclic diols with sulfuryl chloride

“…Recently, ionic liquids have been employed as solvents for such reactions, with the advantage that sulfuryl chloride is hydrolytically stable in this medium. 12 These direct methods are however not generally applicable and complex mixtures may result from simple alkyl substituted acyclic 1,2-diols. The problem has been attributed to: (a) the intrinsic ring strain of cyclic sulfates slowing down the final cyclisation, and (b) the innate chlorinating power of sulfuryl chloride.…”