Monobenzoate esters

Jacobsen reported that the Co(salen) complex 10 catalyzed the addition of carboxylic acids to meso-epoxides [20]. An initial screen revealed that benzoic acid and its derivatives were the most useful nucleophiles from the perspective of reactivity and selectivity. Although optical purities exceeding 90% ee were observed only with selected substrates, the crystalHnity of the benzoate esters in some cases allowed enhancement of their enantiopurity by recrystallization. The ring opening of cyclohexene oxide, for instance, proceeded on a multigram scale in quantitative yield and 77% ee subsequent recrystallizations of the monobenzoate ester 11 then afforded 98% ee material isolated in 75% yield (Scheme 7). 

Monobenzoate esters are prepared by the esterification of benzoic acid with one molar equivalent of alcohol, usually 2-ethylhexanol, isononanol, or isodecanol. Monobenzoates are not used as primary plasticizers but as secondary plasticizers where they help reduce plastisol viscosities, lower the fusion or processing temperatures, and give a boost to stain resistance in formulations based on GP plasticizers. Both mono and dibenzoate esters can be used in non-PVC materials such as acrylic films and caulks, latex coatings, polysulfide sealants and coatings, and polyurethanes. 

Marans and co-workers used pentaerythritol trinitrate (81) to synthesize a number of aryl and alkyl esters, including the formate, propionate (84), oxalate, succinate, benzoate (85), 3,5-dinitrobenzoate (86), and ortho-, meta-, and para- (87) nitrobenzoate esters. The para-nitrobenzoate ester (87) has also been prepared from the nitration of pentaerythritol monobenzoate with mixed acid. ... 

In an effort to obtain a salvinorin derivative possessing an oe-diol system which can be transformed into the dibenzoate ester required for the exciton chirality CD method, salvinorin A (1) or B (2) was treated with sodium borohydride in various protic solvents. The products having the la,2a-diol group were obtained in high yield. However, this reduction was accompanied by extensive isomerization at C-8. While mechanistic details for this unexpected observation remain to be established at this time, the isomerization at C-8 appears to be the result of the base-promoted clevage of the C-8/9 bond under the reaction conditions followed by the reclosure to provide the 8-epimer prior to the reduction of the 1-ketone. Furthermore, attempts to obtain the 1,2-dibenzoate derivative of the major reduction product 3 under various benzoylating conditions invariably produced only the 2-monobenzoate. 

The carbonyl and 2,3-double bond of pyran-4-ones and their monobenzo derivatives are reducible and therefore attempts to reduce functional groups such as carboxaldehyde, carboxylate ester, carboxylic acid chloride or nitrile need careful selection of reagents. The reducibility of a particular group varies with the nature of other substituents present and it is not possible to generalize about the conditions required for each reaction. 

The synthesis of bisalkynyl benzoates from bisalkynyliodonium triflates with sodium benzoate or p-nitrobenzoate in dichloromethane has also been reported (equation 89)43. The bisalkynyl esters are sensitive to hydration of the triple bonds, especially in solution, and have been isolated only in low yields. When R = H, monobenzoate derivatives are also obtained. 

J = 7.5 Hz). Other structural features clearly recognizable are a quaternary C—CH3 (t9.03, 3H singlet), H—C—OH (t5.5, IH multiplet), H—C—OCO (approx. t5.26, IH), and OH (t4.97, IH singlet) (151). One of the two hydroxyls is tertiary (resistant to acetylation and oxidation) and the other secondary. Heteratisine forms a basic monoacetate (CCCXCVI) and monobenzoate (CCCXCVII). The latter is identical with the naturally occurring benzoyl ester (145,146). The monoacetate with... 

Beilstein Handbook Reference) 1,3-Benzenediol, monobenzoate Benzoic acid, m-hydroxyphenyl ester BRN 1873897 Eastman Inhibitor RMB EINECS 205-241-7 3-Hydroxyphenyl benzoate NSC 4807 Resorcinol monobenzoate. Industrial grade UV absorber/stabilizer for cellulosic plastics and PVC formulations. White crystalline solid mp = 133-135" insoluble in H2O, CeHe, soluble in EtOH, MezCO LDso (rat orl) = 1600 mg/kg. Eastman Chem. Co Monomer -Polymer Dajac. 

Racemic cii-diols 48. and were prepared as previously described by catalytic osmic oxidation of acronycine (IJ and 6-demethoxyacronycine (17 ). respectively. Treatment of those diols with excess acetic anhydride afforded the corresponding diesters 6 and 67., respectively. When only one equivalent of anhydride was used, monoesters at the less hindered 2-position, such as acetate and benzoate 69. were obtained. Treatment of the monobenzoate 69, with excess acetic anhydride furnished the mixed ester JR-... 

Note Plasticizers for PVC also include special-purpose products in plications such as flooring (benzyl phth ates) st resistance (monobenzoates or benzyl phflialates) food and film wrap (adipate esters with siq)erior low-temperature and ... 

As may be seen from Fig. 6.6, the latter compound has no band at 1733 cm" , whereas the D-talose monobenzoate has a strong ester carbonyl band there. Hence, the compound of interest here is not an orthobenzoate but a benzoate. It was thought to be 1-0-benzoyl-a-D-talose, but was later shown (Wood and Fletcher, 1957) to be the /S-D-anomer (XXI). 

Benzoic acid, m-hydroxyphenyl ester 3-Hydroxyphenyl benzoate Resorcinol, monobenzoate... 

UV stabilizers (particularly the hydroxybenzophenones and the hydroxybenzotriazoles). Also, blend ABS with PVC or cap the ABS part with a stable film like acrylic. Some hindered amines are also being used especially in blends with absorber systems Absorbers, quenchers and HALS are used, but only absorbers are recommended for protecting whatever is underneath an acrylic substrate Aryl esters (resorcinol monobenzoate). Also salicylates, hindered amines, then benzophenones, and the benzotriazoles... 

Chemical cellulose esters are relatively stable to UV radiation since they lack aromatic chromophores. Even so, exposure to UV radiation may cause some chain scission and loss of physical properties in cellulose esters exposed to outdoor environments esters formulated for such use must be stabilized accordingly. Some resorcinol and benzophenone derivatives, such as resorcinol monobenzoate and 2-hydroxy-4-methoxybenzophenone, are reportedly excellent UV-light stabilizers for cellulose esters (56,57). Other stabilizers include piperidine derivatives (58) and substituted triazole compounds alone (59) and in combination with resorcinol monobenzoate (60). 

Monobenzoates and dibenzoates dominate the types of benzoates commercially available. The largest producer of benzoate esters is Velsicol Chemical Corporation their trade name is Benzoflex . Listed below are the various types of benzoate plasticizers manufactured by Velsicol ... 

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