H-CHD

If (Z)-propene-l-d undergoes hydrogen exchange via either n-propyl or sec-propyl species, the relative contribution of n-propyl and sec-propyl species is reasonably expected to be 76 % and 24% as described in Eq. (15). Based on this relative contribution of n- and sec-propyl species the isomers formed from (Z)-propene-l-d, were calculated to be 82.4% (E)-propene-l, l-d2 and 17.6 % propene-1, 1 -d2, in excellent agreement with the experimental values of 81.6% (E)-propene-l,2-d2 and 18.4% propene-1, 1 -d2. The yields of all isomers obtained in this experiment are in good agreement with the calculated values as listed in Table VI, and the participation of l-propenyl-l-djfCHj—C H=CHD) and that of the 2-propenyl-l-d,... 

Zzk. CaM/J h[chd mnMl cdajwu Ifrtyt r likkA l rUiap(hl fY)dftu4jxl ... 

Figure 3. Absorption spectrum of the transient observed 3 ps after laser excitation of an Ar-saturated 2.25 x 10 m 208 acid solution (pH 5) containing 0.4 M formate ion and 1 X 10 M benzene. The solid and dashed (—..—) lines show the literature absorption spectra of the HO-CHD" and H-CHD radicals of benzene, respectively. The inset shows the literature spectrum of the H-CHD of benzoic acid. " ...

The radical anion of benzene is reported to present an absorption maximum at 290 nm in aqueous solution and two absorption maxima at approx. 285 and 385 nm in a matrix at 77 Since the radical anion of benzene is known to protonate to H-CHD on a microsecond time-scale, the latter radical may be detected with our laser equipment. Figure 3 shows the spectrum of the transient species obtained, along with that of the H-CHD and HO-CHD radicals of benzene" " whose participation in the overall reaction has already been discussed (see above). The observed transient shows important contributions of the H-CHD and HO-CHD radicals however, absorption at wavelengths higher than 340 nm cannot entirely be attributed to these radicals. 

Ketterer, M. W., and Maercklein, G. H., Caffeinated beverage use among Type A male patients suspected of CAD/CHD A mechanism for increased risk Stress Medicine 7(2), 119-124, 1991. 

CHD Re (CO) j. are very close to the gas phase positions and the shift (Mn to Re) is almost identical in gas phase and matrix. Thus, V(C-H). in the matrix will provide information on the C-H bond length. On generation of the unstable 1 2 complexes, there is a downward shift in V(C-H). of 11-14 cm implying a bond lengthening of. 0011-.00 X. This is clearly a very sensitive probe of the effect of slight electronic perturbation of the metal centre and is likely to be useful for other systems. 

In our hands, this gave as principal product on reaction with pyridine the complex [PtCl2(py) CHD=C(Me)CDMe2 ] and not the product shown in equation (3). This reaction is complicated by a side reaction apparently involving 8-elimination from one of the methyl substituents, but an analysis similar to that described above by H, 13C 1H and 2H 1H NMR spectroscopy showed that the major product was formed by the a-elimination pathway (15). 

The peroxyl radical formed in this reaction, as well as by OH and H hydrogen abstraction from CHD, can react with another oxygen molecule after intramolecular addition of the peroxyl radical to the double bond to give an endoperoxidic radical (equation 21). 

Thermolysis of 44 produced products derived from the Myers-Saito cyclization reaction. However, when 43 having a trimethylsilyl substituent at the acetylenic terminus was subjected to heating in the presence of 1,4-CHD at 70 °C for 3 h, the 1H-cyclobut[a]indene 46 was produced. A reaction mechanism involving an initial Schmittel cyclization to generate the benzofulvene biradical 45 followed by an intramolecular radical-radical coupling was proposed to account for the formation of the formal [2 + 2]-cycloaddition product 46. 

In the presence of 1,4-cyclohexadiene (CHD) the C4-centred radical pathway was diverted from formation of artennuin D, 13, to afford significantly more deoxyartemisinin 3 (by the secondary C4 radical abstracting a H-atom from CHD) while the proportion of 21 remained the same. The authors proposed that the 02 pathway (Scheme 3) contributed most to the activity and that the C4 secondary radical intermediate (generated by... 

XXV P-Deuteroacrylsaure- isopropylester CHD=CH-COOiC,H, CjHsMgBr in Toluol bei -78 C eine Mischung erythro-und threo-ditaktisch 106)... 

PHOSPHOLIPID SYNTHESIS. Phospholipids were synthesized (H.Schuster, S.S. Hall, and R.Mendelsohn, in preparation) according to the procedures of Tulloch (26), modified with more modern and efficient coupling steps, and scaled up to produce 2-3 grams of specifically deuterated material. Derivatives were fully characterized with NMR, MS, FT-IR, and Differential Scanning Calorimetry (DSC). Purity is estimated from NMR data at > 98X. The extent of deuteration, as estimated from the residual intensity of the CHD rocking modes at... 

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