Alias reduction

Thomas Lectka of Johns Hopkins University has reported (J. Org. Chem. 68 5819,2003) that benzoylquinine (BQ) catalyzes the two-carbon homologation of a ketene, derived from the acid chloride, with chloroamide such 7, to give the (3-amino acid derivative 8 with control of both relative and absolute configuration. The authors suggest that the BQ is involved five times in the course of the transformation of 6 into 8. The two esters of the product are differentiated, so one can imagine, inter alia, reduction of... 

Alias reduction for hybrid filter banks. One possible problem of all cascaded filter banks specific to hybrid filter banks needs to be mentioned. Since the frequency selectivity of the complete filter bank can be derived as the product of a single filter with the alias components folded in for each filter, there are spurious responses (alias components) possible at unexpected frequencies. Crosstalk between subbands over a distance of several times the bandwidth of the final channel separation can occur. The overall frequency response shows peaks within the stopbands. 

Both acids 3deld succinic acid, m.p. 185°, upon catalytic reduction (see Section 111,150), thus establishing their structures. Maleic and fumaric acids are examples of compounds exhibiting cis-trans isomerism (or geometric isomerism). Maleic acid has the cm structure since inter alia it readily 3delds the anhydride (compare Section 111,93). Fumaric acid possesses the trans structure it does not form an anhydride, but when heated to a high temperature gives maleic anhydride. 

Yohimbine (36) is a well-known and reasonably available alkaloid from Corynanthe yohimbe, inter alia. For this reason, and partly because of its intrinsic pharmacological activity (including reputed aphrodisiac activity), chemists have frequently studied its properties. Oppenauer oxidation is usually attended by saponification and decarboxylation in this series, and yohimbone (37) is the product. Wolf-Kischner reduction to yohimbane (38), followed by sodium hydride mediated alkylation, leads to the analgesic agent, mimbane (39). °... 

In the following, some selected classes of reactions and applications of Ni11 polyazamacrocyclic complexes are discussed. Other applications include, inter alia, the electrochemical reduction of allyl ethers1613 and the epoxidation of alkenes.1614... 

The reactions of carbon dichalcogenides other than C02 with Ni° have also been studied quite intensively.2460,2461 Inter alia, Ni polymeric complexes with metallic properties have been prepared using CS2 as the starting material.2462 Some further impetus was given by the observation that CS2 can mimic the binding of CO to the CODH enzyme active site, although CS2 itself does not undergo oxidation/reduction and does not appear to bind to center C (the site of CO oxidation and C02 reduction).2463... 

Peroxidases have been implicated in carcinogenesis by PAH, aromatic amines, and estrogens inter alia (6-9). These enzymes catalyze the reduction of hydrogen peroxide and organic... 

In the different volumes of this new series we will feature catalysts for oxidation and reduction reactions, hydrolysis protocols and catalytic systems for carbon-carbon bond formation inter alia. Many of the catalysts featured will be chiral, given the present day interest in the preparation of single-enantiomer fine chemicals. When appropriate, a catalyst type that is capable of a wide range of transformations will be featured. In these volumes the amount of practical data that is described will be proportionately less, and attention will be focused on the past uses of the system and its future potential. 

This procedure could in principle open the way, inter alia, to the phosphono analog of D-glucose 1-phosphate simply by reacting the gluconolactone 56 with LiCH2PO(OMe)2 and then reducing Ae obtained lactol 59. Unfortunately the lactol phosphonate 59 was inert to this reduction (Scheme 16). 

The reasons for the non-attainment of the PM10 limit values were also stated in the notifications of time extensions. In most cases, it was stated that non-attainment by 2005 could be attributed inter alia to a delay in the implementation of measures, or certain measures leading to a lower level of emission reductions than expected. An increase in road traffic is stated as a reason for non-attainment especially in eastern European countries. An increase of primary NO2 emissions due to an increasing share of diesel vehicles has been reported e.g. by France, Germany, Italy and UK. 

Serum creatinine is ubiquitously used as an indicator for GFR despite the knowledge that a substantial proportion of patients with reduced GFR display serum creatinine levels within the normal range and that even a 50% reduction of GFR not infrequently is associated with a normal concentration of serum creatinine (L8, P5, S3). The usefulness of serum creatinine as a marker for GFR is limited by, inter alia, the influence of an individual s muscle mass on the production rate of creatinine (H8, P5, S5), by the tubular secretion and reabsorption of creatinine, by the dietary intake of creatine and creatinine, and by analytical difficulties (P5). These significant limitations in the use of serum creatinine as an indicator for GFR has made it of interest to search for better indicators for GFR. Several recent studies have compared the use of serum cystatin C and creatinine as markers for GFR as determined by golden standard procedures based upon determinations of the... 

Besides the simple reduction, a di-, tri-, or polymerization may thus result, depending, inter alia, on the concentration of the compound and the availability of protons. The overall electron consumption decreases in comparison with that indicated by the polarographic wave. 

In the presence of dienes or alkynes, identical reduction of (136) yields ReCp Cl2(diene) and ReCp Cl2(RC=CR). The latter has an interesting chemistry which includes inter alia hydrolysis to form ReCp (0)(RC=CR), alkylation to give ReCp Me2(RC=CR), and a series of H+-catalyzed coupling reactions with alkenes to form ReCp Cl2(diene) and ReCp Cl(dienyl). ... 

Cycloheptatriene reacts with elemental sulfur in sulfolane at 70 °C and in the presence of pyridine in such a way that an S3 unit is added across the 1,6-positions, resulting in 2,3,4-trithiabicyclo[4.3.1] deca-6,8-diene (21% yield). Trimethylvinylsilane, Me3SiCH=CH2, and sulfur react at 55 °C in the presence of Fe3(CO)i2 to give, inter alia, l-trimethylsilyl-2,3,4,5,6-pentathiacycloheptane. The preparation of cycUc trisulfanes from alkenes and Sg has also been carried out by reduction with NaH in toluene in the presence of a phase transfer catalyst. Indole fused pentathiepines were obtained by lithiation of indole or N-methylindole followed by thionation with elemental sulfur. ... 

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