Independent generator

The diastereoselectivity of the zinc iodide catalyzed reaction of the azetidinone I with the trimethylsilyl enolate derivatives of the chiral 3-(l-oxopropyI)oxazolidinones 6 was considerably lower (about 60 40), although independent generation of the zinc enolate, via exchange of the lithium enolate with zinc bromide, afforded the /9-Iactam carboximide derivatives in a ratio (RIS) 80 20177. 

The intermediates (7) have been independently generated in aqueous solution. Note the similarity of this mechanism to those of insertion of CH2 (18-9) and of O (18-19). The three reactions are essentially analogous, both in products and in mechanism. Also note the similarity of the latter part of this mechanism to that of the Beckmann rearrangement (18-17). 

When alkynyldisilanes 13a and b were photolyzed in the presence of freshly generated dimesitylsilylene (Mes2Si ), the silylene added to the Si=C double bond of 1-silaallenes 14a and b to form disilacyclopropanes 15a and b (Scheme 5). Even without the independently generated silylene, photolysis of 13b produced 15b in 8% yield, but compound 13a gave only traces of 15a. In the case of 15b, the dimesitylsilylene most likely originated from silacyclopropene 16. 

In the above sections we have supposed that pharmaceuticals are conventional goods and that their market shows no essential differences from any other normal market. The effects of co-payment that we have studied will occur if a number of conditions are fulfilled, including the condition that the rational and perfectly informed consumer is an independent generator of demand. The phenomenon of induced demand and incomplete agency relationships, together with uncertainty as to the effectiveness of alternative treatments and doses, can cloud these theoretical results. In this section we analyse to what extent the pharmaceutical market fulfils or fails to fulfil these conditions. 

In addition, the presence of the same element concentration (in our example, Th) in both the coordinates introduces a strong artificial correlation of no meaning in terms of process. Using a random number generator, e.g., in a spreadsheet, the reader may check that randomly and independently generated values of Ta and Th usually produce quite good correlations in Th/Ta vs Th diagrams. This topic is specifically dealt with in Section 4.2. 

The next section deals with the use of independently generated tert-butoxy transient species which are capable of abstracting... 

TABLE 9. Oxidation of X-substituted benzyl alcohols with Trametes villosa laccase and R2NO—H mediators in buffered (pH = 4.5) water solution at 25 °C. Comparison of p (vs. [Pg.726]

The single step conversion of methyl acetate to ethylidene diacetate is catalyzed by either a palladium or rhodium compound, a source of iodide, and a promoter. The mechanism is described as involving the concurrent generation of acetaldehyde and acetic anhydride which subsequently react to form ethylidene diacetate. An alternative to this scheme involves independent generation of acetaldehyde by reductive carbonylation of methanol or methyl acetate, or by acetic anhydride reduction. The acetaldehyde is then reacted with anhydride in a separate step. 

If the distribution function of electrons in the cavity f(e,t) were not allowed to fluctuate, the contacts would be independent generators of current noise whose zero-frequency energy-resolved cumulants ((/ R))e could be obtained from a quantum-mechanical formula... 

If the voltage is high enough, the noise of isolated contacts can be considered as white at frequencies at which the distribution function / fluctuates. This allows us to consider the contacts as independent generators of white noise, whose intensity is determined by the instantaneous distribution function of electrons in the cavity. Based on this time-scale separation, we perform a recursive expansion of higher cumulants of current in terms of its lower cumulants. In the low-frequency limit, the expressions for the third and fourth cumulants coincide with those obtained by quantum-mechanical methods for arbitrary ratio of conductances Gl/Gr and transparencies Pl,r [9]. Very recently, the same recursive relations were obtained as a saddle-point expansion of a stochastic path integral [10]. 

Zhang R, Wang Y (2003) Independent generation of 5-(2 -deoxycitydinyl)methyl radical and formation of a novel cross-link lesion between 5-methylcytosine and guanine. J Am Chem Soc 125 12795-12802... 

Bansal KM, Patterson LK, Schuler RH (1972) Production of halide ion in the radiolysis of aqueous solutions of the 5-halouracils. J Phys Chem 76 2386-2392 Barnes JP, Bernhard WA (1994) One-electron-reduced cytosine in acidic glasses conformational states before and after proton transfer. J Phys Chem 98 887-893 Barvian MR, Greenberg MM (1992) Independent generation of the major adduct of hydroxyl radical and thymidine. Examination of intramolecular hydrogen atom transfer in competition with thiol trapping.Tetrahedron Lett 33 6057-6060... 

Barvian MR, Greenberg MM (1995) Independent generation of 5,6-dihydrothymid-5-yl and investigation of its ability to effect nucleic acid strand scission via hydrogen atom abstraction. J Org Chem 60 1916-1917... 

Carter KN, Greenberg MM (2003) Independent generation and study of 5,6-dihydro-2 -deoxyuri-din-6-yl, a member of the major family of reactive intermediates formed in DNA from the effects of y-radiolysis. J Org Chem 68 4275-4280... 

Barvian MR, Greenberg MM (1992) Independent generation of the major adduct of hydroxyl radical and thymidine. Examination of intramolecular hydrogen atom transfer in competition with thiol trapping. Tetrahedron Lett 33 6057-6060... 

Tronche C, Goodman BK, Greenberg MM (1998) DNA damage induced via independent generation of the radical resulting from formal hydrogen atom abstraction from theCI - position of a nucleotide. Chem Biol 5 263-271... 

The independent generation and reactivity of allenic enolates has been investigated.15 Under kinetic conditions, these highly reactive species are protonated in the a,p-7t plane with preference (E) to the larger ( group. Under thermodynamic con- (g) ditions, addition/elimination equilibrates the two product stereoisomers. The kinetic protonation stereochemistry has been found a function of solvent, proton donor, and donor concentration. 

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