2-Methyl-2-propanethiol

Acid-Gatalyzed Synthesis. The acid-catalysed reaction of alkenes with hydrogen sulfide to prepare thiols can be accompHshed using a strong acid (sulfuric or phosphoric acid) catalyst. Thiols can also be prepared continuously over a variety of soHd acid catalysts, such as seoHtes, sulfonic acid-containing resin catalysts, or aluminas (22). The continuous process is utilised commercially to manufacture the more important thiols (23,24). The acid-catalysed reaction is commonly classed as a Markownikoff addition. Examples of two important industrial processes are 2-methyl-2-propanethiol and 2-propanethiol, given in equations 1 and 2, respectively. 

The piefeiied route depends upon the avajlabihty of a hydrogen atom in the beta-position to the thiol group. In other words, a-toluenethiol (in toluene) decomposes to give 1,2-diphenylethane and hydrogen sulfide, via the homolytic route, whereas 2-methyl-2-propanethiol decomposes to give 2-methyl-1-propene and hydrogen sulfide. 

Figure 13.8.2 2-Methyl-2-propanethiol or rert-butyl mercaptan, an example of an odorant and warning agent for natural gas.

Related sulfur-containing derivatives are formed from the reaction of 49 with 2-methyl-2-propanethiol, cyclo-hexanethiol, and 2-propanethiol in toluene at ambient temperature. The resulting tetrameric cyclopentadienyl thiolato complexes [(if-Cp)Mg(/.t3-SR) ]4 (R = Bu, CgFIn, Pr1) are colorless crystalline solids. Treatment of... 

Individually indexed compounds are f Butanethiol, 1712 f 2-Butanethiol, 1713 Dodecanethiol, 3567 f Ethanethiol, 0933 f Methanethiol, 0489 f 2-Methylbutane-2-thiol, 2023 f 3-Methylbutanethiol, 2024 f 2-Methylpropanethiol, 1715 f 2-Methyl-2-propanethiol, 1716... 

For the synthesis of selenocysteine derivatives that are suitable for peptide synthesis essentially two approaches have been used to date (1) conversion of p-chloroalanine 23 or serine-O-tosylate derivatives 24 into the desired selenocysteine derivatives by a nucleophilic displacement reaction with an areneselenol and (2) full reduction of selenocystine and in situ reaction with aryl halides to produce the aryl selenides. 7 25 In this context, reduction of selenocystine in 2 M NaOH with 2-methyl-2-propanethiol for concomitant formation of the mixed selenide/sulfide derivative 5e-(tert-butylsulfanyl)selenocysteine in analogy to the formation of 5-(fett-butylsulfanyl)cysteine 26 fails as a consequence of the difficult reduction of the diselenide with monothiols. 27 ... 

The stereochemistry of conjugate additions requires similar considerations to those used to predict nucleophilic attack on a carbonyl. Acyclic substrates may yield up to three contiguous chiral centres (Scheme 18). The relative stereochemistry of carbons C(l) and C(2) will depend upon the approach of the two reagents. The stereochemistry of carbon C(3) will depend upon the lifetime of the intermediate 30 if it has even a short lifetime it will take up the most stable conformation. For example, the base-catalysed additions of ethanol-d and 2-methyl-2-propanethiol-d to ethyl crotonate give a (2R, 3R )/(2R, 3S ) diastereoisomeric ratio of the addition products of approximately 10 190. The authors90 suggest the reaction proceeds in two steps and the protonation of the enolate determines the stereoselectivity. 

Methyl phenyl sulfone Methylphosphonic acid 2-Methylpropanal 2-Methylpropane 2-Methyl-1 -propanethiol 2-Methyl-2-propanethiol Ht, 0.972 at-121.6°C ... 

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