Sulfonate esters reactions with

An aiyl methane- or toluenesulfonate ester is stable to reduction with lithium aluminum hydride, to the acidic conditions used for nitration of an aromatic ring (HNO3/HOAC), and to the high temperatures (200-250°) of an Ullman reaction. Aiyl sulfonate esters, formed by reaction of a phenol with a sulfonyl chloride in pyridine or aqueous sodium hydroxide, are cleaved by warming in aqueous sodium hydroxide. ... 

Reactions of Organic Fluorine Compounds Table 13. Reactions of Sulfonate Esters with Nucleophiles... 

The importance of reactions with complex, metal hydrides in carbohydrate chemistry is well documented by a vast number of publications that deal mainly with reduction of carbonyl groups, N- and O-acyl functions, lactones, azides, and epoxides, as well as with reactions of sulfonic esters. With rare exceptions, lithium aluminum hydride and lithium, sodium, or potassium borohydride are the... 

Some 40 research articles resulted from Tipson s 18 years at the Mellon Institute, and they demonstrate that he was able to sustain some of his interest in carbohydrate chemistry, and he continued to study the reactions of sulfonic esters with sodium iodide. In 1945 he compiled his published work into a senior thesis for the D.Sc. degree that was awarded by the University of Birmingham. However, a considerable proportion of the research at the Mellon Institute was never published because of patent restrictions. This was particularly true for his work on carbohydrates and other organic compounds conducted after July 1952, when he was assigned to the Parke, Davis and Company Fellowship in Medicinal Chemistry to synthesize potential antiviral and anticancer agents. 

In addition to these physical studies at the Bureau, Tipson was able to return to his synthetic interests, both alone and in collaboration with other staff members. He was especially pleased to prepare D-talose in crystalline form, an accomplishment that had eluded Emil Fischer. Pursuing his longstanding interest in the reaction of sulfonic esters with iodide and following an earlier observation that the tetratosyl ester of erythritol is converted into butadiene by the action of sodium iodide and zinc, he demonstrated (with A. Cohen) that nonterminal unsaturation may be conveniently introduced into alditol derivatives by reaction of contiguous secondary sulfonates with sodium iodide and zinc dust in boiling A.A-dimethylformamide. This Tipson-Cohen reaction subsequently proved of great utility in other hands for the conversion of more complex carbohydrate structures into vicinal dideoxy derivatives. 

Polymerization in a single-phase homogeneous solution in THF/water mixtures (2 1) has also been reported [235]. Such reactions allowed for the preparation of a poly (p-phenylene) with sulfonate ester and dodecyl side groups [Eq. (10)]. By comparison to the aforementioned biphasic polymerizations, the synthesis of polymers with higher degrees of polymerization was reported in the solution procedure. 

Primary tosylates are more prone than bromides to form f-butyl ethers by Sn2 displacement by the f-butoxide anion in DMSO. Sulfonate esters of flexible cyclic and secondary acyclic alcohols give predominately alkenes in the presence of f-BuOK/DMSO. With sulfonate esters of 3-hydroxy steroids, there is competition between /S-elimination and attack of the f-butoxide ion on sulfur to form alcohols mesylates are more prone to this reaction than tosylates. Sulfonate esters of 3a-acetoxy-12a-hydroxycholanate undergo mainly /3-elimination with f-BuOK/DMSO (eq 4). In this case, substitution of various other aprotic solvents for DMSO and DMSO Na+ for f-BuOK was not as effective. Treatment of both the mesylate and the tosylate of cholesterol with f-BuOK/ DMSO gives the conjugated diene, 3,5-cholestadiene, in high yield. ... 

Compounds 12-14 were prepared by direct displacement reactions of the PEG tosylate or mesylate. In the ether preparations, the 19-crown alcohol and octadecanol were first treated with sodium hydride. In these reactions the sulfonate esters were substantially more reactive than the bromide, and offered the additional advantage that their reactions could be monitored by disappearance of the sulfonate UV absorption using HPLC. 

The concept of the conjugation reaction with sulfone 75 is presented in Equation 3.44. The nucleophilic addition of the heterocyclic nitrogen of the aromatic ring to the double bond affords intermediate 76, which upon elimination of tolyl-sulfinic acid forms a, 3-unsaturated ester 77. A second Michael addition finally gives cyclic bis-alkylated product 78 (Equation 3.44). 

Very few 4-aminothiazoles have been synthetized directly. The reaction of a-halonitriles with thioamides generally fails and only extensive decomposition results. However, the benzene sulfonic ester of mandelonit-rile reacts with thiobenzamide to give 2,5-diphenyl-4-aminothiazole (257), Ri = R2 = Ph, in 37% yield (Scheme 132) (417) Similarly, a-cyano-a-acetylthioacetamide condensed with a-chloroacetonitrile give 257, Ri = CH(CN)CH3 and R2 = H (804). 

The reaction of alcohols with acyl chlorides is analogous to their reaction with p toluenesulfonyl chloride described earlier (Section 8 14 and Table 15 2) In those reactions a p toluene sulfonate ester was formed by displacement of chloride from the sulfonyl group by the oxygen of the alcohol Carboxylic esters arise by displacement of chlonde from a carbonyl group by the alcohol oxygen... 

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