Benzoate derivative

Another internal acetal, methyl 2-0-benzoyl-3,4-0-benzylidene-/ -D-arabinopyranoside 103 (84), behaves in an analogous manner, except that the isomeric 4-bromo (104) and 3-bromo (105) benzoate derivatives are formed in a ratio of 1 1. The identity of 104 (l-xylo) can be deduced from its mode of formation from a presumed benzoxonium ion (106)... 

The occurrence of 3,4-dihydroxybenzoate decarboxylase was also found widely in facultative anaerobes. Among them, Enterobacter cloacae P241 showed the highest activity of 3,4-hydroxybenzoate decarboxylase, and the activity of the cell-free extract of E. cloacae P241 was determined to be 0.629 p.mol min (mg protein) at 30°C, which was more than that of C. hydroxybenzoicum, 0.11 (xmol min mg protein)" at 25°C. The E. cloacae P241 enzyme has a molecular mass of 334 kDa and consists of six identical 50 kDa subunits. The value for 3,4-dihydroxybenzoate was 177 p.M. The enzyme is also characteristic of its narrow substrate specificity and does not act on 4-hydroxybenzoate and other benzoate derivatives. The properties of E. cloacae P241 3,4-hydroxybenzoate decarboxylase were similar to those of C. hydroxybenzoicum in optimum temperature and pH, oxygen sensitivity, and substrate specificity. 

On the other hand, Becker et al. also have attempted the anodic oxidation of RfCH2CH2I in acetonitrile and they have achieved the anodic transformation of C8F, 7CH2CH2I to the corresponding acetamide, trifluoroacetate, and benzoate derivatives in good yields [35]. They propose a different reaction mechanism involving a hypervalent iodanyl radical intermediate as shown in Eq. 17. 

Highly enantioselective variants of these processes employ a cyclometallated iridium C,0-benzoate derived from allyl acetate, w-nitrobenzoic acid, and... 

More recently, using the cyclometallated iridium C,(7-benzoate derived from allyl acetate, 4-methoxy-3-nitrobenzoic acid and BIPHEP, catalytic carbonyl crotylation employing 1,3-butadiene from the aldehyde, or alcohol oxidation was achieved under transfer hydrogenation conditions [274]. Carbonyl addition occurs with roughly equal facility from the alcohol or aldehyde oxidation level. However, products are obtained as diastereomeric mixtures. Stereoselective variants of these processes are under development. It should be noted that under the conditions of ruthenium-catalyzed transfer hydrogenation, conjugated dienes, including butadiene, couple to alcohols or aldehydes to provide either products of carbonyl crotylation or p,y-enones (Scheme 16) [275, 276]. 

A mixture of m- and p-nitrobenzoyl peroxide reacts with titanocene in THF solution to form the corresponding [(n -Cp)2Ti(02CC6H4N02)2] benzoate derivatives. The i.r. spectra of these compounds suggest that they involve unidentate carboxylato-groups. [(7i-Cp)2Ti(NCO)2] and [(7i-Cp)2Ti(NCS)2]... 

Herbicidal Activity of Various Benzoate Derivatives Control Rates in Kg/Ha... 

For the mono-C-glycosylphenol, the commercially available 2,4,6-trihydroxyacetophe-none was chosen and selectively methylated at C-2 and C-4. The partially protected phenol was glycosylated with the C-benzyl-protected glucosyl trichloroacetimidate in the presence of trimethylsilyl triflate as promoter to give directly a C-(benzyl protected)glycosylphenol. The unprotected hydroxyl group of this compound was converted with benzoyl chloride into a fully protected C-glycoside phenol. Treatment of the benzoate derivative with sodium hydroxide in... 

The structure of the benzoate derivative 166 was established by X-ray analysis, confirming the selective oxidation of the sulfur atom at the 6-position of thieno[2,3- ]thiophene-2-sulfonamides. The activated double bond of the cyclic vinyl sulfone moiety readily underwent nucleophilic addition, which was exemplified by reaction of 165 with 4-methoxybenzylthiol in the presence of base to provide a mixture of 167 and 168 <1999JHC249>. 

Other examples of absolute configuration determination by the exciton coupling between a chromophore and a benzoate derived from the alcohol include ... 

Exciton coupling is also observed in methacrylate derivatives of allylic alcohols151 and in a benzoate derivative of a homoallylic alcohol152. For benzoates of propargylic alcohols of S configuration 11 in which the O-Bz bond is assumed anti to the C-R1 bond, a Dc Voe calculation predicts a positive benzoate Cotton effect, in accordance with experimental153. 

Hewawasam, P., Chen, X., Ding, M., Starrett, J. E., (Bristol-Myers Squibb) Benzoate derivatives of diaryl... 

Figure D1.3.1 A typical HPLC chromatogram of cholesterol benzoate derived from dried egg yolk.

Methanol used for the HPLC measurement should be of HPLC grade with low absorbance at UV wavelengths below 230 nm. Dried-proc-essed foods usually include a relatively large amountof oxidized cholesterol analogs (Smith, 1996). The benzoate derivatives of these oxides do not separate from cholesterol benzoate by HPLC. Therefore, the GC measurement is more suitable for the determination of cholesterol in dried products with a high level of the oxidized cholesterol. 

For GLC and HPLC analysis, the extraction of total lipids from food requires overnight separation of the organic layer. If the sample volume is small, however, centrifugation of the extract may shorten the sample preparation time. Cholesterol derivatization requires <2 hr depending on the number of samples. The peak of TMS ether and cholesterol benzoate derivatives will be eluted within 10 min after the injection of the sample. 

The N1C1-MS (negative ion chemical ionization-mass spectrometry) of the pentafluoro-benzoate derivative of 42 has been identical to the corresponding derivative of [4,4-D2]HPB. The levels of HPB released from hemoglobin of NNK-treated rats, determined using [3,3-D2]- and [4,4-D2]-HPB standards, were the same40. 

Polysaccharide-based CSPs also exhibit a chiral recognition for alcohols and a large number of resolutions have been reported. Chiral alcohols can usually be directly resolved with hexane containing a small amount of an alcohol as the eluent. For aliphatic alcohols, which cannot be directly resolved, their resolution is often efficiently attained as phenylcarbamate or benzoate derivatives on OD (Figure 17).85 For example, 2-butanol and 2-pentanol are completely resolved with a very high selectivity on OD as their phenylcarbamates. The derivatization of alcohols to phenylcarbamates and benzoates can be easily achieved by the reaction with phenyl isocyanates and benzoyl chlorides, respectively. In most cases, the phenylcarbamates are better resolved than the benzoates. For chiral compounds bearing phenolic hydroxy groups, the addition of a small amount of an acid to an eluent is recommended to depress its dissociation. 

Treatment of methyl 2-(2-cyano-2-(ethylthio)-l-phenylvinyloxy)benzoate derivatives 749 with A1C13 in nitrobenzene affords 3-cyanoflavones in moderate yield (Equation 301) <2003TL9283>. 

Oxygen-atom transfer to PPh3, and to olefins to give epoxide, has been accomplished via (Ph3P)2Pt02 in the presence of electrophiles such as benzoyl chloride (90) transfer occurs from a peroxyben-zoatobisphosphine intermediate (Ph3P)2Pt(OOCOPh)Cl (cf. 6 in Scheme 1), which is converted to the benzoate derivative. 

In a separate investigation by the author (4) Step 2 benzoate derivatives, (II), were prepared and were also effective as opioid receptor antagonists and used as antipruritic agents. 

Ballini, R., Barboni, L., Fiomi, D., Giarlo, G., and Pahnieri, A. 2005c. One pot synthesis of 3,5-alkylated acetophenone and methyl benzoate derivatives via an anionic domino process. Chemical Communications, 20 2633. ... 

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