2,5-dideutero, preparation

The dimer has been shown by Blackburn and Davies40 to have a geometrical structure similar to that of thymine dimer (10). The proof consisted in observation of the 13C—H satellite NMR spectrum of 5,5 -dideutero-,3,3 -dimethyl uracil dimer (prepared by methylation of the dimer from photolysis of uracil-5-rf). The magnitude of the H6H6 coupling constant showed that these hydrogens were vicinal, and was... 

The method measures cortisone (urinary free cortisone, UFE), cortisol (urinary free cortisol, UFF), 6/1-hydroxycortisol, and 18-OHF using deuterated internal standards [62]. Commercial tetradeuterocortisol was used as an internal standard for cortisol, and the remaining dideutero homologs prepared in the laboratory by deuteration of A1 analogues. UFF and UFE are considered better indicators of hormone availability and hypersecretion than the F and E (free plus conjugated) quantified in the comprehensive profile. Typically the values of total F and E are about three times that of... 

Deuterated Model Compounds and Protodedeuteration Rate Measurements. Protodedeuteration rate studies were outlined for 2,4,6-trideuterophenol and 2,4,6-anisole, 3,5-dideutero- and 4,6-dideutero-guaiacols, 3,5-dideuteroveratrole, 5-deutero-4-hydroxy-3-methoxytoluene, and 2,6-dideutero-4-hydroxy-3-methoxytoluene (6). Using appropriate combinations of acid- and base-catalyzed deuterium exchange reactions, the following deuteroderivatives were prepared in this study 3,5-dideutero-and 4-deutero-2,6-dimethoxyphenols, 4,6-dideutero- and 5-deutero-1,2,3-trimethoxybenzenes, and 2,6-dideutero-4-hydroxy-3,5-dimethoxytoluene. 

The 5-deutero and 4,6-dideutero derivatives of 1,2,3-trimethoxy-benzene were prepared by methylating the corresponding deuterated 2,6-dimethoxyphenols with dimethyl sulfate in 10% NaOH at room temperature. 

In several preparations of deuterium labeled analogs, elimination of deuterium bromide was much slower than that of hydrogen bromide, suggesting an EicB mechanism for the elimination. Thus, in the preparation of cis- and rans -l,2-dimethyl-3-methylenecyclopropane (17), formation of the dideuteromethylene analogs took 7 days at room temperature, as opposed to 14 hours for the unlabeled compounds. In the case of endo- and exo-2-methyl-6-methylene-bicyclo[3.1.0]hexane (19), the dideutero analog also required heating to 45°C to complete the reaction. ... 

In order to disprove one of these alternatives, the dideutero analog 4.1 was prepared and the rates were measured for the fragmentation of... 

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