Inversion toluenesulfonate

The hydrolysis of sulfonate esters of 2 octanol is stereospecific and proceeds with complete inversion of configuration Write a structural formula that shows the stereochemistry of the 2 octanol formed by hydrolysis of an opti cally pure sample of (S) (+) 1 methylheptyl p toluenesulfonate identify the prod uct as / or S and deduce its specific rotation... 

Apparently, the first use of this reaction in the sugar series was in the preparation33 of tetra-0-acetyl-l-0-tosyl- a -D-glucopyranose (probably the /3-derivative actually, by Walden inversion at carbon atom 1) by the action of silver p-toluenesulfonate on tetra-O-acetyl-a-D-glucopyranosyl bromide in boiling, dry diethyl ether ... 

The hydrolysis of (S)-(+)-1 -methylheptyl p-toluenesulfonate proceeds with inversion of configuration, giving the R enantiomer of 2-octanol. 

In Section 8.14 of the text we are told that optically pure (S )-( I )-1-methylheptyl /Holuenesulfonate is prepared from optically pure (S)-(+)-2-octanol having a specific rotation [a]o +9.9°. The conversion of an alcohol to a p-toluenesulfonate proceeds with complete retention of configuration. Hydrolysis of this /Holuenesulfonate with inversion of configuration therefore yields optically pure (R)-(-)-2-octanol of [ ]d -9.9°. 

The hydroxyl group must be replaced by azide with inversion of configuration. First, however, a leaving group must be introduced, and it must be introduced in such a way that the configuration at the stereogenic center is not altered. The best way to do this is to convert (R)-sec-butyl alcohol to its corresponding p-toluenesulfonate ester. 

Treatment of the p-toluenesulfonate with potassium acetate in acetic acid will proceed with inversion of configuration to give the desired product. 

The substrates are secondary alkyl -toluene sulfonates, and so we expect elimination to compete with substitution. Compound B is formed in both reactions and has the molecular formula of 4-ferf-butylcyclohexene. Because the two p-toluenesulfonates are diastereomers, it is likely that compounds A and C, especially since they have the same molecular formula, are also diastereomers. Assuming that the substitution reactions proceed with inversion of configuration, we conclude that the products are as shown. 

The second step is a nucleophilic substitution in which benzoate ion displaces p-toluenesulfonate with inversion of configuration. 

The 1,2-diols formed by the asymmetric oxidation can be used as substrates in a wide variety of transformations. Conversion of the hydroxy groups to p-toluenesulfonates then allows nucleophilic displacement by azide at both centers with inversion of configuration (Scheme 9.22).161... 

Reactions of organomagnesium compounds with dialkyl sulfates or alkyl sulfonates often give satisfactory yields of the products of displacement of sulfate or sulfonate. Side-reactions have been observed, but they can often be avoided for example, an excess of the sulfate or sulfonate should be used with Grignard reagents, as some is consumed by nucleophilic attack by halide ion [A]. The dialkyl sulfates are reactive, but hazardous. Toluenesulfonates (tosylates) are less reactive, but their reactions are catalysed by copper complexes the reactions of trifluoromethanesulfonates (triflates) are catalysed by nickel complexes. Reactions of Grignard reagents with secondary tosylates appear to follow an Sn2 mechanism, with inversion of configuration [43],... 

Transamination of Tris with Methylamine by Inverse Addition. A 2-L, three-neck flask was fitted with a mechanical stirrer and two Claisen adapters. One Claisen adapter was fitted with a reflux condenser and a CH3NH2-sparging tube that could be immersed in the reaction solvent. The other Claisen adapter was fitted with a pressure-equalizing dropping funnel and a thermometer that could be immersed in the reaction solvent. The reflux condenser and addition funnel were also fitted with N2 adapters. The flask was charged with heptane (500 mL) and p-toluenesulfonic acid (p-TSA) monohydrate (6.10 g, 0.032 mol) in a N2 atmosphere. The reaction mixture was heated to reflux temperature, and CH3NH2 was introduced at a continuous rate. 

A quite different result is obtained when the reaction conditions are modified. For example, when compound XIII is taken up in hot benzene containing a catalytic amount of -toluenesulfonic acid, not only is an oxazoline obtained in which the absolute configuration of the unsymmetrical carbon (starred atom of Scheme 14.3) in the starting aziridine is retained (only 1% inversion), but the structurally isomeric oxazoline XV is produced also. ... 

Since p and E are vector quantities, a, P, 7, etc., are tensors. For example, the electric field vector in the first term will have three components in the molecular coordinate system. Each electric field component can contribute to polarization along each of the three directions in the molecular coordinate system. This triple contribution of electric field components leads to a total of nine elements to the second rank polarizability tensor. Similarly, there are 27 components to the P tensor and 81 components to 7. Molecular symmetry generally reduces these tensors to only a few independent elements. Unless the molecular coordinate system lacks an inversion center, the form of the odd-rank tensors such as P will lead to zero induced polarization in this representation of optical nonlinearities. For molecules such as benzene and polymers such as poly[bis(p-toluenesulfonate)diacetylene]... 

Bicyclopentane reacted with acetic acid at 86 °C to give acetoxycyclopentane (27 a, 47%) and cyclopentene (29a, 53%). In the presence of /7-toluenesulfonic acid a substantial amount of tosyloxycyclopentane was isolated. Deuterio- and methyl-substituted bicyclo[2.1.0]pentane derivatives were submitted to acid-catalyzed and uncatalyzed acetolysis reactions. The distribution of products was analyzed and the rates of reaction calculated. It was shown that the acetolysis of the extremely strained bicyclopentane proceeds mainly via inversion of configuration at both ends of the central bond when it was cleaved. 5,5-Dimethylbicyclo[2.1.0]pentane (31) reacted via cleavage of one of the outside C —C bonds, leading to 1-cyclobutyl-1-methyl-ethyl products 33, rather than via cleavage of the central bond. ... 

The reactions of Na2[Fe(CO)4] with alkyl halides or alkyl / -toluenesulfonates proceed with inversion in stereochemistry via Sf 2 mechanism (eq (9)) [39]. 

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