Isopropanol deuterated

Our kinetic investigation of this reaction provides compelling evidence for an atom abstraction mechanism. Quenching of the triplet excited state of 1 by various alcohols occurs only when an a-hydrogen is present ( 19). No quenching occurs with -butanol or triphenyl-carbinol. Furthermore, completely deuterated isopropanol yields a kinetic isotope effect of 1.5 (Table II). 

The scission of a C-C bond is negligible in the case of ethanol (1.5%) and of minor importance in the case of isopropanol (5.5%). Studies with deuterated isopropanols dissolved in undeuterated isopropanol indicate that the C-C bond is largely broken by the molecular processes 13 and 14 and only to a minor extent by homo-lytic scission (reaction 15) (132). 

The evidence for the formation of the sulfene intermediate, probably via a concerted E2 type elimination reaction, has been reviewed by King and Rathore. For instance, when the reaction shown in Equation 11 was performed using deuterated isopropanol (MczCHOD), the monodeuterated isopropyl sulfonate 10 was obtained (90% yield). The presence of a fi ee sulfene intermediate was also indicated by mass spectral evidence in the reaction of ethylsulfonyl chloride with deuterated methanol (MeOD) in the presence of 3-methylpyridine. Further evidence for sulfene formation derived from kinetic studies of the reaction of methylsulfonyl chloride with isopropanol in the presence of triethylamine. The... 

At low acidity the relative rates of oxidation of isopropanol and (CH3)2CDOH (contaminated with light isopropanol) were found to be 6.4+1.9 at 40 °C after correction for incomplete deuteration has also been determined and the... 

The resolution of the overall reaction into steps implied by the steric effect (above) has been achieved" for the oxidation of isopropanol. In 97% aqueous acetic acid a rapid reaction, ic2 x 1.25x10 l.mole . sec (15 °C, p = 0.183 Af NaC104), which is unaffected by deuteration, precedes the oxidation. Evidence for an intermediate has been reported for the oxidation of 1,1,1-tri-fluoro-2-propanol at very high acidities . 

Golden DM, Bierbaum VM, Howard CJ (1990) Comments on reevaluation of the bond dissociation energies AHDBE for H-OH, H-OOH, H-O, H-O, H-OO, and H-OO. J Phys Chem 94 5413-5415 Gray P, Herod AA (1968) Methyl radical reactions with isopropanol and methanol, their ethers and their deuterated derivatives. Trans Faraday Soc 64 2723-2734... 

Figure 4 Example of the application of chrom-NMR/HRMAS with regular NMR solvents and bare silica as a solid phase. Left panel aromatic molecule homologues in deuterated chloroform benzene, naphthalene and anthracene. Right panel alcohol mixture ethylene glycol, phenol, isopropanol in deuterated water. Adapted with permission from Ref. 53. Copyright 2008 Elsevier.

One of the first examples of a secondary isotope effect is Cohen and Westheimer s (138) report that chromic acid oxidation of isopropanol is 10% slower when both methyl groups are fully deuterated. According to the authors mechanism, this is a proton abstraction reaction, but, even if so, it is a rather complicated one, involving prior formation of the chromate ester, so no attempt will be made to rationalize the effect. 

The enantiomers of isopropanol deuterated in one methyl group have been prepared. In an interesting experiment, Mislow et al. (139) attempted to use one enantiomer in the asymmetric reduction of a raceinic ketone, having exceptionally high rotatory power ... 

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