Stereoselective syntheses of 3-aminocyclooctanetriols and halocyclooctanetriols

The efficient synthesis of two new stereoisomeric 3-aminocyclooctanetriols and their new halocyclitol derivatives starting from cis,cis-1,3-cyclooctadiene are reported. Reduction of cyclooctene endoperoxide, obtained by photooxygenation of cis,cis-1,3-cyclooctadiene, with zinc yielded a cyclooctene diol followed by acetylation of the hydroxy group, which gave dioldiacetate by OsO4/NMO oxidation. The cyclooctane dioldiacetate prepared was converted to the corresponding cyclic sulfate via the formation of a cyclic sulfite in the presence of catalytic RuO4. The reaction of this cyclic sulfate with a nucleophilic azide followed by the reduction of the azide group provided the target, 3-aminocyclooctanetriol. The second key compound, bromotriol, was prepared by epoxidation of the cyclooctenediol with m-chloroperbenzoic acid followed by hydrolysis with HBr(g) in methanol. Treatment of bromotriol with NaN3 and the reduction of the azide group yielded the other desired 3-aminocyclooctanetriol. Hydrolysis of the epoxides with HCl(g) in methanol gave stereospecifically new chlorocyclooctanetriols.

Synthesis and Evaluation of Cyclic Sulfite Diesters as Sulfur Dioxide (SO2) Donors

<div>Although sulfur dioxide (SO₂) finds widespread use in the food industry as its hydrated form, sulfite, a number of aspects of SO₂biology remain to be completely understood. Among the tools available for intracellular enhancement of SO₂, most suffer from poor cell permeability and a lack of control over SO₂ release. We report 1,2-cyclic sulfite diesters as a new class of reliable SO₂donors that dissociate in buffer through a nucleophilic displacement to produce SO₂with tuneable release profiles. We provide data in support of the suitability of these SO₂donors to enhance intracellular levels of SO₂at an efficiency superior to sodium bisulfite, the most commonly used SO₂ donor for cellular studies.</div>

Synthesis and Evaluation of Cyclic Sulfite Diesters as Sulfur Dioxide (SO2) Donors

<div>Although sulfur dioxide (SO₂) finds widespread use in the food industry as its hydrated form, sulfite, a number of aspects of SO₂biology remain to be completely understood. Among the tools available for intracellular enhancement of SO₂, most suffer from poor cell permeability and a lack of control over SO₂ release. We report 1,2-cyclic sulfite diesters as a new class of reliable SO₂donors that dissociate in buffer through a nucleophilic displacement to produce SO₂with tuneable release profiles. We provide data in support of the suitability of these SO₂donors to enhance intracellular levels of SO₂at an efficiency superior to sodium bisulfite, the most commonly used SO₂ donor for cellular studies.</div>