Synthesis of deuterated compounds

Denitration of nitro compounds with Bu3SnD provides an elegant method for the synthesis of deuterated compounds.98 Recently, the synthesis of deuterium labeled plant sterols has been reported (see Eq. 7.78).99... 

Synthesis of deuterated compounds, 65 Synthesis, use of blocking groups in, 215... 

When we first approached the study on the determination of the cannabinoids by mass spectrometry, we were somewhat intimidated by the large number of possible metabolites. We were also concerned about the requirement of deuterated analogs of the compounds for mass spectrometric determination. The difficulties involved in the synthesis of nonlabeled compounds, however, argued for an approach that did not require total synthesis of the deuterated analogs. 

The Synthesis of Deuterium Derivatives 1.5.7.1. by Interconversion of Deuterated Compounds... 

The deuterated compounds 79 and 80 have been prepared60 in the course of synthesis of 2,2,2(2H3)diazoethane 81 (equation 32). The latter is a very useful reagent for the synthesis of deuterated ethyl esters and is generated in excellent yield from 80, which is more stable61 and less toxic than other precursors62,63. 80 has been prepared in three steps from trideuterioacetonitrile in 71.3% overall yield. It is possible to suppress the formation of... 

Small deuterated compounds such as HaCCOO H and C Hal are easily incorporated into long-chain acids as in the following anodic synthesis of deuterated stearate. 

The use of deuterated organosilicon hydrides in conjunction with proton acids permits the synthesis of site-specific deuterium-labeled compounds.59 126 221 Under such conditions, the deuterium atom in the final product is located at the charge center of the ultimate carbocation intermediate (Eq. 62). With the proper choice of a deuterated acid and organosilicon hydride, it may be possible to use ionic hydrogenation in a versatile manner to give products with a single deuterium at either carbon of the original double bond, or with deuterium atoms at both carbon centers.127... 

One of the best procedures for the synthesis of 1,3-diphenylbenzo[c]furan (138) consists of the reaction of 3-phenylphthalide (102) with phenylmagne-sium bromide, 2- especially when the reaction mixture is worked up in the presence of hydroquinone. The primary product can be isolated as colorless crystals with mp 145°C (decomposition above 100°C) in the presence of acid this unstable compound loses water very rapidly. The stereochemistry of the hydroxyphthalan is not known with certainty presumably the cis isomer (137a) is formed first. In deuterated acetone equilibrium with the trans isomer (137b) is established. ° For the synthesis of 1,3-diphenylbenzo [cjfuran, the hydroxyphthalan need not be isolated. 

After criticism [142] of the interglycosidic NOEs observed in the previously described study a very precise approach towards the conformational analysis of thea-(l-3) bond was performed by NOE measurements of specifically deuterated compounds [143], The conformation was determined earlier by several interglycosidic NOEs to protons that have their resonances in an area of high spectral overlap. The synthesis of C-deuterated di- and trisaccharides made an unequivocal assignment of the enhanced signals possible. Thus, the enhancements of H2, H3, and H4 of the P-D-mannose upon irradiation of Hl. as well as the enhancement of HS. upon irradiation of HS. man are indicative of the rigid conformation at the glycosidic bond and confirmed the previous study. 

As a consequence, benzylic protons in a- and y-alkyl groups (but not in p-positions) are acidic and in water are in equilibrium with the corresponding methylenepyrans water at pH <5. Because the symmetric y-methylenepyrans (y-anhydrobases) are more stable than a-methylenepyrans [57], the isotopic exchange with deuterium oxide proceeds about ten times faster in y than in a, and this allows the synthesis of regiospecifically deuterated alkylpyrylium salts, which can then be converted into other deuterated compounds because the reaction with nucleophiles takes place even faster [58, 59],... 

The investigated compounds were synthesized according to methods given in the literature [2,3,5]. The synthesis of the partially deuterated analogues was accomplished analogously, but using as solvents H20-D20 mixtures with appropriate compositions. 

Sulfonimidothiazolines, 317, 318 Sulfonyl halides, with 2-aminothiazoles, 69 Sulfur (Sg), in synthesis of, A-4-thiazoline-2-thione, 373 Sulfur compounds, 69 Sulfuric acid, with alcohols, 38, 47, 80, 90 in bromination, 77 dealkylation by, 39 deuterated, 92 diazotization with, 66 in nitrations, 72 rearrangements in, 73, 113 Sulfuryl chloride, 432 Symbiotic behavior, see HSAB theory Symmetry. C2v and C2p, 120 Synthetic fibers, 154... 

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