2- ethyl tosylate

A thiol, usually under basic catalysis, can undergo Michael addition to an activated double bond, resulting in protection of the sulfhydryl group as a substituted S-ethyl derivative. Displacement of an ethyl tosylate by thiolate also affords an S-ethyl derivative. 

Phenethyl tosylate solvolyzes in CF3C02H orders of magnitude faster than ethyl tosylate (Figure 2.25). Because the neighboring phenyl ring can make a -electron pair available, a phe-nonium ion intermediate is formed. Phenonium ions are derivatives of the spirooctadienyl... 

Clearly, both spectra are of the tertiary 2-methylbutyl cation and the neopentyl cation never saw the light of day. The reaction is the same rearrangement that you saw in the substitution reaction of neopentyl iodide, but here the rate of rearrangement can be measured and it is extremely fast. Ncopentyl tosylate reacts to form a cation under these conditions about 104 times as fast as ethyl tosylate, even though both tosylates are primary. This massive rate difference shows that if migration of an alkyl group can allow rearrangement to a more stable carbocation, it will happen, and happen rapidly. 

Examination of the Sn2 reaction between ethyl tosylate and halide ions in hexamethylphosphoric triamide (fir = 29.3) with a variety of counter ions [Li , [n-C4H9)4N ] has shown that the rates obtained with Hthium salts are always higher than those with the corresponding tetra-n-butylammonium salts [341]. This is in contrast to the situation observed in acetone [279]. This means that, in this particular solvent, lithium salts are more dissociated than tetraalkylammonium salts. This has indeed been confirmed by conductivity measurements [341, 342], The lithium cation apparently has specific interactions with strong EPD solvents such as [(CH3)2N]3PO cf. Section 3.3.2). 

Ethyl tosylate and isopropyl tosylate were evaluated as precursors of />-tolue-nesulfonic acid [38]. It was presumed that these esters would decompose at elevated temperatures as shown in Scheme 4.4. 

The residual styrene contents in PS prepared by the polymerization of styrene in the presence of ethyl tosylate (1 mol%) initially increased upon heating to 260 °C but then decreased with time (Table 4.3). After 2h, residual styrene levels were reduced to an undetectable level. Isopropyl tosylate is much... 

ETHYL-p-TOLUENESULFONATE see EPW500 ETHYL TOSYLATE see EPW500 ETHYI.-P-TOSYLATE see EPW500 ETHYL... 

For example, ethyl tosylate, which has the leaving group on a 1° carbon, reacts with NaOCH3 to yield ethyl methyl ether, the product of nucleophilic substitution by an 8 2 mechanism. It reacts with K0C(CH3)3, a strong sterically hindered base, to yield ethylene by an E2 mechanism. 

In 1985, Warner and Norton (50) reported an alternative synthesis of [Re(C2H5)(CO)5] they reacted Na[Re(CO)s] with excess ethyl tosylate to give the desired product [Eq. (II)]. This report also included the synthesis of isobutyl rheniumpentacarbonyl from the treatment of Na[Re(CO)s] with isobutyl tosylate [Eq. (11)]. 

---