Search results for "Smiles rearrangement"
showing 3 items of 3 documents
A Carbohydrate-Based Julia–Kocienski Reagent for Syntheses of Chain-Extended and C-Linked Saccharides
2014
The carbohydrate-derived Julia–Kocienski reagent 2-{[(3aS,4S,6R,6aR)-6-methoxy-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl]methylsulfonyl}-1,3-benzothiazole (6) was prepared from d -ribose and investigated in the eponymous olefination. The base-promoted generation of the Julia anion induced a rearrangement to the corresponding l -lyxose epimer 2-{[(3aS,4R,6R,6aR)-6-methoxy-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl]methylsulfonyl}-1,3-benzothiazole (12), which reacted readily with aldehydes and with a gluconolactone. The latter reaction furnished an exo-glycal-linked C-diglycoside.
Transamidation reactions of 2-(2-sulfonylguanidino)acetamides
2007
Abstract The reactivity of a series of sulfonylguanidinoacetamides 2A–E towards amines is reported. Guanidinoacetamides 2A–C, containing the arylsulfonylimino moiety, undergo a facile transamidation to give substituted carboxamides 4A–C, through the imidazolidinone intermediate 3. Acetamide 2D, having a methanesulfonylimino substituent, affords the imidazolidinone 3D and no transamidated carboxamides 4 are detected. In the case of guanidinoacetamide 2E, with a p-nitrobenzenesulfonylimino substituent, a Smiles rearrangement was observed.
Synthesis of new hybrid 1,4-thiazinyl-1,2,3-dithiazolyl radicals via Smiles rearrangement
2017
The condensation reaction of 2-aminobenzenethiols and 3-aminopyrazinethiols with 2-amino-6-fluoro-N-methylpyridinium triflate afforded thioether derivatives that were found to undergo Smiles rearrangement and cyclocondensation with sulphur monochloride to yield new hybrid 1,4-thiazine-1,2,3-dithiazolylium cations. The synthesized cations were readily reduced to the corresponding stable neutral radicals with spin densities delocalized over both 1,4-thiazinyl and 1,2,3-dithiazolyl moieties. peerReviewed