2.4.5- Trimethylphenyl acetate

The rate of anisole acylation depended on the acetate (Table 2). Initially it was about 1.5 times greater with p-tolyl acetate and with 2-methoxyphenyl acetate than with phenyl acetate, slightly lower with 2-methoxyhydroquinone diacetate, 2.5 times lower with the hydroquinone diacetate and very low with 2,4,6-trimethylphenyl acetate. The low reactivity of this latter acetate can be related to limitations in the rate of diffusion of this bulky compound in the BEA zeolite pores. Furthermore, a greater reactivity of this acetate was found with HFAU zeolites whose pore size is greater. Curiously, with hydroquinone diacetate (but not with the 2-methoxyhydroquinone acetate), there was a quasi immediate deactivation. We are carrying out additional experiments so as to understand how the reactivity of aromatic acetates changes with their nature and the zeolite acidity and porosity. 

Obtained by reaction of aluminium chloride on a mixture of 2,4,6-trimethylphenyl acetate or 4-methylphenyl acetate and 2-chloro-4-methylphenyl benzoate without solvent at 150° (67% yield and small amounts, respectively) [2535]. m.p. 91° [2151,2535] pKJ2516],... 

Obtained (by-product) by Fries rearrangement of 2,4,5-trimethylphenyl acetate (pseudocumenol acetate) with aluminium chloride at 130-140° [2596],... 

Isopentylphloroacetophenone. 2, 4, 6 -Trihydroxy-3 -isopentylacelophenone, 1055 Isopseudocumenol acetate. 2,3,5-Trimethylphenyl acetate, 869 Isosordidone dimethylether. 6-Chloro-5,7-dimethoxy-2,8-dimethylchromone, 861 Isothymol methylether. 4-Methyl-2-isopropylanisole, 919 Isovaleraldehyde. 3-Methylbutanal, 991... 

AUtylmagnesium halides and dialkyhnagnesium compounds are efficient metallating agents toward alkyl mesityl ketones such as Kohler s ketone (2,2-diphenylethyl 2,4,6-trimethylphenyl ketone) and hindered carboxylic esters such as f-butyl acetate. 

A recent study by Ishibashi and coworkers104 found that the reaction of trimethylphenyl-silane with methyl chloro(methylthio)acetate in the presence of tin(IV) chloride gave no ipso substitution (equation 41). This was attributed to steric factors, since when the primary chloride ClCH2SCH2C02Et was used, a 20% yield of ipso-substituted product was obtained. 

For the preparation of Gly- j/-[CF=CH]-Pro in relation to the study of cyclophilin A inhibitors, Welch and co-workers employed the Peterson reaction of a-fluoro-a-trimethylsilyl acetate (15a,b) with ketone 10. E/Z selectivity was found to be influenced by the ester part of the acetate (see Scheme 10.4) [15]. The reaction of tert-butyl ester 15a gave almost an equal amount of the isomers (lib, E Z= 1 1.1), while moderate E selectivity was observed when trimethylphenyl ester 15b was used (11c, E Z= 6 1). Conversion of ester Z-llb to amino derivative 16 was achieved via the Mitsunobu reaction of phthalimide with the alcohol formed by the DIBAL-H reduction of Z-llb. 

MeOsalen = N,N/-ethylenebis(5-methoxysalicylideneiminate) Me3tacn = /V,/V/,/V//-trimethyl-1,4,7-triazacyclononane MMAO = modified methylaluminoxane MMTP = l-methoxy-2-methyl-l-trimethylsiloxypropene MOCVD = metal organic chemical vapor deposition Ms = mesityl = 2,4,6-trimethylphenyl NBD = norbornadiene NBS = iV-bromosuccinimide NitOH = p-nitrophenol Np = 3-neopentyl OAc = acetate OBz = benzoate... 

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