Benzoylbenzoate ester

An example of a photolabile mask for alcohols and thiols employing o-benzoylbenzoate esters is reported by Porter and co-workers [100], Primary and secondary alcohols as well as thiols can be easily masked via the formation of the corresponding 2-benzoylbenzoate esters and converted back into alcohols/ thiols under PET-reductive conditions. Irradiation in isopropanol/benzene 1 1 leads to 3-phenylphthalide dimers as the coproduct (together with acetone), whereas more potent electron donors (e.g., amines) result in the monomers and the corresponding imine. Yields generally range from 60% to 90% (Scheme 55) [100]. 

Gaon, I., Turek, T.C., Weller, V.A., Edelstein, R.L., Singh, S.K., and Distefano, M.D. (1996). Photoactive analogs of farnesyl pyrophosphate containing benzoylbenzoate esters synthesis and application to photoaffinity labeling of yeast protein farnesyltransferase. J Org Chem 61 7738-7745. 

A new and efficient route to endo-hirsutene has been described which uses, as the key step, the oxetane (11) from the intramolecular photocycloaddition of (12) (Rawal et ai), and 3-deoxy-D-arabino-2-heptulopyranosonic acids can be synthesised photochemically from Barton esters such as (13) (Barton and Liu). Interest in the development of photochemically removable protecting groups continues, and the irradiation of the 4-hydroxyphenacyl-protected system (14) is reported to release ATP with a quantum yield of 0.37 (Givens and Park). Benzoylbenzoate esters of primary and secondary alcohols undergo cleavage in the presence of electron donor molecules and it is proposed that such esters could be effective photolabile protecting groups for alcohols and that thiols can be similarly protected (Jones et al.). 

Several carbohydrate applications have been included in a review of micro-wave-assisted organic reactions, and a survey of chemical reagents in photo-aflinity labelling included the role of various base-labelled azido- and thio-nucleosides, sugar azide derivatives and p-benzoylbenzoate esters of nucleosides. A further review intitled Reverse Anomeric Effect Fact or Fiction refers to early evidence based on studies of glycosyl pyridinium and imidazolium salts. It concludes that its origin as an electronic effect is not supported by theory or experimental results. ... 

SCHEME 12 Proposed photo reduction mechanism of benzoylbenzoate esters. ... 

The same sequence of reactions from o-hydroxylated deoxybenzoins (250) forms 3-benzylbenzofurans, e.g., 251.584 Similarly, o-hydroxylated benzils with suitable a-bromoalkanoic esters give 3-benzoylbenzo-furans397,585 (e.g., 253, R = H).586 When R = OMe, the resulting... 

BENZOYL-lH-BENZIMIDAZOL-2-YL)-CARBAMIC ACID METHYL ESTER see MHLOOO p-BENZOYLBENZOIC ACID see BDL860 a-BENZOYLBENZYL CYANIDE see OOK200 BENZOYL CHLORIDE see BDM500 BENZOYL CHLORIDE (DOT) see BDM500 BENZOYL CHLORIDE, METHOXY-(9CI) see AOY250 BENZOYL CYANIDE-o-... 

The A-benzyloxycarbonyl group, which cannot be removed electrochemically in methanol, may be cleaved in DMF [40]. i/ -esters, such u-benzoylbenzoic acid V -ethyl ester, which is an acylated ketal of a benzophenone, may be reduced in an acetate buffer to a phthalide [71]. 

CycUzation catalyst. Newman and Courduvelis5 used the reagent as catalyst for the condensation of o-benzoylbenzoic acid methyl ester (1) with methyl chloro-carbonate. The product (2) decomposes on heating to give the pseudo ester (3). 

In contrast, the adduct (41) obtained from singlet oxygen and l,4-diphenyl-3/7-2-benzopyran-3-one (40) is a stable, crystalline solid (Scheme 2) <78JA2564>. Nonetheless, (41) decomposes in boiling benzene giving o-dibenzoylbenzene (43) and phenyl o-benzoylbenzoate (45) in 85% and 5% yield respectively. No luminescence is detected. The major reaction course is decarboxylation to the intermediate o-xylylene peroxide (42), which can be trapped as its Diels-Alder adduct with maleic anhydride. The ester (45) could have arisen directly from (41) by decarbonylation and concomitant... 

The reaction is reversible and is catalysed by strong acids 95% sulfuric acid, organic sulfonic acids and ZnCl2146 or boron trifluoride147-149 are especially effective. However, if more than 10% of boron trifluoride is used, polymerization intervenes seriously. For good yields of esters the reaction temperature must be kept as low as possible. The preparation of terf-butyl o-benzoylbenzoate will be detailed as an example 150... 

A solution of o-benzoylbenzoic acid (10.0 g) in ether (70 ml) containing 1 ml of concentrated sulfuric acid is mixed with liquid isobutene (100 g) in a 500-ml pressure flask. The flask is closed, kept overnight at room temperature, cooled in ice-salt, and then opened. The contents are poured into a cold solution of sodium hydroxide (40 g) in ice-water (500 ml). The organic phase is separated and dried over potassium carbonate. Evaporation affords the almost pure ester, m.p. 66-70° (8.81 g, 70%). 

Benzoylbenzoates, 347 Benzoyl chloride, 171 Benzoyl cyanide, 35 Benzoylhydrazine, 36 At-Benzoylimidazolc, 35 Benzoyl isocyanate, 35 Bcnzoyl-L-leucine, 193 Benzoyl-L-leucylglycine ethyl ester, 193 Benzoyloxylation, 160 N-Benzoylperoxycarbamic acid, 35-36 N-Benzoyl-N -triflylhydrazine, 36 Benzpyrene-l-ol, 316... 

Benzoylacetyl. See 1-Phenyl-1,2-propanedione Benzoyl alcohol. See Benzyl alcohol Benzoylaminoacetic acid. See Hippuric acid o-(Benzoylamino) diphenyl disulfide. See 2,2 -Dibenzamidodiphenyl disulfide Benzoylbenzene. See Benzophenone 2-Benzoyl benzoic acid methyl ester o-Benzoylbenzoic acid methyl ester. See o-M ethyl benzoyl benzoate 4-Benzoylbiphenyl... 

Synonyms Benzoic acid, 2-benzoyl-, methyl ester Benzoic acid, o-benzoyl-, methyl ester 2-Benzoyl benzoic acid methyl ester o-Benzoylbenzoic acid methyl ester MBB o-(Methoxycarbonyl) benzophenone Methyl 2-benzoylbenzoate Methyl o-benzoyl benzoate Empirical C15H12O3... 

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