Synthesis of α,ω‐Diazidoalditol Derivatives via Both bis‐ or tris‐Cyclic Sulfites and Peracetylated α,ω‐Dibromoalditols as Bielectrophilic Intermediates

Abstract

The α,ω‐diazidoalditol derivatives with erythro, threo, xylo, ribo, D‐arabino, D‐manno, and D‐gluco configuration were efficiently synthesized, respectively, from bis‐ or tris‐cyclic sulfite or peracetylated α,ω‐dibromoalditol intermediates. The cyclic sulfite intermediates has the advantage to lead directly to the free α,ω‐diazido‐α,ω‐dideoxyalditols.     

Asymmetric Synthesis of Allylic Sulfonic Acids: Enantio‐ and Regioselective Iridium‐Catalyzed Allylations of Na2SO3

An enantioselective allylation reaction of allylic carbonates with sodium sulfite (Na₂SO₃) catalyzed by Ir complex was accomplished, providing allylic sulfonic acids in good to excellent yields with a high level of enantio‐ and regioselectivities. (R)‐2‐Phenyl‐2‐sulfoacetic acid, a key intermediate for the synthesis of Cefsulodin and Sulbenicillin, was synthesized as well.     

Radiation-induced radical ions in calcium sulfite

We have used EPR to study the effect of γ radiation on calcium sulfite. We have observed and identified the radiation-induced radical ions SO ₂ ⁻ (iso) with g = 2.0055 and SO ₂ ⁻ (orth-1) with g₁ = 2.0093, g₂ = 2.0051, g₃ = 2.0020, identical to the initial and thermally induced SO ₂ ⁻ respectively, SO ₃ ⁻ (iso) with g = 2.0031 and SO ₃ ⁻ (axial) with g_⊥ = 2.0040, g_∥ = 2.0023, identical to mechanically induced SO ₃ ⁻ . We have established the participation of radiation-induced radical ions SO ₃ ⁻ in formation of post-radiation SO ₂ ⁻ . __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 4, pp. 467–472, July–August, 2006.     

Perfluoroalkylation of 2-mercaptoethanol as a key step for a new synthesis of perfluoroalkyl vinyl sulfides, sulfoxides and sulfones

We have developed a new method of perfluoroalkylation of thiols, using a mixture of sodium formate/sodium sulfite to generate a sulfoxylate radical anion. This method is compatible with alcoholic functionality and was applied to mercaptoethanol. The obtained compounds were transformed into perfluoroalkyl vinyl sulfides, sulfoxides and sulfones.     

Simultaneous determination of trace amounts of sulfite and thiosulfate in petroleum and its distillates by extraction and differential pulse polarography

Simultaneous determination of sulfite and thiosulfate at sub-ppm levels in petroleum and its distillates was investigated using a convenient, accurate and sensitive procedure. This method involved preliminary extraction of the sample followed by detection via differential pulse polarography (DPP) at a dropping mercury electrode. In this procedure, an appropriate amount of sample was shaken with a recommended volume of 0.25% (w/w) sodium acetate solution. The mixture was filtered in two steps and was then ready for DPP. The method was free from interferences from hydrogen sulfide, elemental sulfur, organic sulfides, and thiophene. Various instrumental factors such as scan rate, pulse height, initial and final potential, and purge time were optimized. The 3σ detection limits were 410 and 125 ng g⁻¹ for sulfite and thiosulfate, respectively. At 5 μg g⁻¹ level in samples, the relative standard deviations (n=4) were 2.51 and 1.15% for sulfite and thiosulfate, respectively. The proposed method was applied to real samples containing input feeds, distillates and fuel oils from Abadan Petroleum Refinery in the south of Iran.     

Concise synthesis of 3-deoxy-d-manno-oct-2-ulosonic acid (KDO) as a protected form based on a new transformation of α,β-unsaturated ester to α-oxocarboxylic acid ester via diol cyclic sulfite

A concise synthesis of KDO (1) as the suitably protected form (2) from 2,3:5,6-di-O-isopropylidene-α-d-mannofuranose (3) was achieved in five steps (overall 65% yield). The key step is the efficient transformation of readily available α,β-unsaturated ester to α-oxocarboxylic acid ester. The newly β-elimination of the corresponding diol cyclic sulfite and the in situ trap (DBU/TMSCl) into enol silyl ether was developed to give the tautomeric equivalent of α-oxocarboxylic acid ester. The deprotection of acid labile TMS ether provided the desired product.     

Comparison of the properties of chemical cellulose pulps

The literature related to differences between chemical cellulose pulps produced by different pulping processes has been reviewed. Kraft pulps tend to be stronger, particularly in tear strength, while sulfite pulps hydrate and beat more readily. Organosolv pulps tend to mirror the properties of sulfite more than those of kraft pulps. A number of theories have been offered to explain the different properties of the chemical pulps; however, none has been universally accepted. It may be that acidic processes develop weak points in the fibers which are magnified in tear strength losses since, at a constant tensile strength, a 10% loss in fiber strength can lead to a 25–30% loss in tear strength. The effects of acidic pulping may also be magnified in greater fiber breakage and damage in the subsequent refining stages. However, strength improvements for inferior pulps can be realized through post-chemical treatments. Caustic treatments appear to give the greatest improvements, presumably due to increases in acidic group content which results in enhanced swelling properties, and possible subtle reorientation of cell wall polymers. The strength of hornified, recycled fibers can also be enhanced with such treatments, although simple beating will restore considerable strength, but at the expense of drainage rates. It is clear that the processes are complex and involve both the chemistry and physics of the fibers and how these attributes combine to affect the subsequent beating of the fibers for bonding and strength development.     

Solubilities of Magnesium Sulfite

Literature data of solubility of MgSO₃ in water and in aqueous solutions of MgSO₄ have been correlated. Magnesium sulfite forms hexahydrate (stable below 40°C) and trihydrate (above 40°C), nevertheless, metastable hexahydrate can precipitate at temperatures significantly higher than this transition temperature. Magnesium sulfate increases the solubility of the sulfite. This revised version was published online in August 2006 with corrections to the Cover Date.     

Ethylene sulfite based electrolyte for non-aqueous lithium oxygen batteries

Non-aqueous lithium–oxygen(Li–O_2) batteries have been considered as the superior energy storage system due to their high-energy density, however, some challenges limit the practical application of Li–O_2 batteries. One of them is the lack of stable electrolyte. In this communication, a novel electrolyte with ethylene sulfite(ES) used as solvent for Li–O_2 batteries was reported. ES solvent showed low volatility and high electrochemical stability. Without a catalyst in the air-electrode of Li–O_2 batteries, the batteries showed high specific capacity, good round-trip efficiency and cycling stability.     

Physicochemical study of rhodium sulfite

Diamagnetic rhodium sulfite Na₁₅(NH₄)₃[Rh₄(μ-SO₃)₆(SO₃)₇(H₂O)₅]·10H₂O was synthesized. An X-ray photoelectron spectroscopy study and chemical analysis revealed that rhodium in this compound was in the oxidation state 2+. The thermal and chemical properties of the compound were investigated. Based on XRPA, IR, and EPR spectroscopy and analytical data about the chemical properties, a hypothesis about the structure of the complex has been formulated.