Tert -Butyl cinnamate

Baker s yeast catalyzed the regioselective cycloaddition of stable aromatic nitrile oxides ArCNO [Ar = 2,6-C12C6H3, 2,4,6-Me3C6H2, 2,4,6-(MeO)3C6H2] to ethyl cinnamate, ethyl 3-(p-tolyl)acrylate, and tert-butyl cinnamates (218). Reactions of dichloro- and trimethoxybenzonitrile oxides with all three esters proceeded regio- and stereoselectively to form exclusively alkyl tran.v -3,5-diary 1 -... 

The conjugate addition of (K)-N-methyl-N-a-methylbenzyl amide 33 to tert-butyl cinnamate 34, followed by an asymmetric aldol reaction and subsequent N-oxidation/Cope elimination afforded the -substituted homochiral Baylis-Hillman product 39 in good yield (Scheme 7) [37]. This chemistry requires the use of stoichiometric rather than catalytic amounts of the chiral base. 

Optically active magnesium amide can add to a, -unsaturated esters such as tert-butyl cinnamate to give /l-amino esters with excellent diastereoselectivity (>95% d.e.) and in good yield (90%) (Scheme 3.42). 

The asymmetric synthesis of aziridines can be achieved by a number of methods. The best alkene substrates are typically a,3-unsaturated esters, styrenes or chromenes, with aziridination by PhI=NTs and a metal-chiral ligand complex. For example, aziridination of tert-butyl cinnamate 73 occurs highly enantioselec-tively with copper(I) triflate and a bisoxazoline ligand (5.77). 

Successful results have been obtained (Renfrow and Chaney, 1946) with ethyl formate methyl, ethyl, n-propyl, iso-propyl, n-butyl, i o-butyl, sec.-butyl and iso-amyl acetates ethylenegl3rcol diacetate ethyl monochloro- and trichloro-scetates methyl, n-propyl, n-octyl and n-dodecyl propionates ethyl butyrate n-butyl and n-amyl valerates ethyl laurate ethyl lactate ethyl acetoacetate diethyl carbonate dimethyl and diethyl oxalates diethyl malonate diethyi adipate di-n-butyl tartrate ethyl phenylacetate methyl and ethyl benzoates methyl and ethyl salicylates diethyl and di-n-butyl phthalates. The method fails for vinyl acetate, tert.-butyl acetate, n-octadecyl propionate, ethyl and n-butyl stearate, phenyl, benzyl- and g aicol-acetate, methyl and ethyl cinnamate, diethyl sulphate and ethyl p-aminobenzoate. 

Under the same test conditions on the basis of melt flow rate, compounds 1 2, 3 and 4 provide significantly better performance than BHT, T and i8 when used in conjunction with phenolic AO-1 (neopentanetetrayl-tetrakis[3,5-di-tert.-butyl]-4-hydroxyhydro-cinnamate). Compounds 2, 2 and 4 also develop less color than BHT and 13. Compounds 6 and 1 develop the most color in the presence of AO-1. ... 

Good-rite 3125 (hindered phenol) B. F. Goodrich Co. 3,5-Di-tert-butyl-4-hydroxyhydro-cinnamic acid triester with 1,3,5 -tris(2-hydroxy-ethyl)-s-triazine-2,4,6(1H,3U,5fl)-trione... 

Pentaerythrityl-tetrabis-(3,5-di-tert-butyl-4-hy- droxy-cinnamate) 1176.0 - 20.0... 

Acid fragment 3 was rapidly prepared by 1,3 dipolar cycloaddition of the requisite cinnamate 17 with tert-butyl azomethine ylide 16. However, the synthesis of the azomethine ylide 15 required rather harsh conditions in the alkylation step and suffered low yield in the methoxymethylation due to its inherent instability. This provided a racemic mixture of 3,4-tranY-disubstimted pyrrolidine... 

A three component coupling reaction involving carbopallada-tion of the aryne followed by a Fleck coupling with tert-butyl acrylate affords oFtAo-substituted cinnamic acids in good yields (eq 11). An ene reaction between the aryne, generated in THF at room temperature, and an alkyne creates allenylbenzenes in moderate yields. The reaction of jr-allylpalladium species with the benzyne created from 2-(trimethylsilyl)phenyl triflate provides access to several types of products in multicomponent... 

Excellsnt color stability FDA regulated Numerous physical forms Synergist with other AO s Chemical Structure Octadecyl 3,5-di-tert-butyl-4-hydroxyhydro-cinnamate... 

The initial asymmetric synthesis (see Scheme 5.2) of pyrrolidine acid 3 suffered from a chiral HPLC bottleneck. As a result, chiral salt resolution was investigated. The rapid discovery of a crystalline di-p-toluoyl-D-tartaric acid salt provided the necessary means to resolve and purify the desired diastereomer. Using 0.65 equivalent of the acid in methyl (cr(-butyl ether (MTBE), the crystallized salt was shown to be a 92 8 ratio of (3S,4R) (3R,4S) diastereomers. The resolved tartaric acid salts were then recrystalhzed from n-butanol to ratios of >99 1 in a 42% overall yield on a 2-kg scale. Further improvements were made in the preparation of the azomethine ylide precursor 38. In step 1, using dimethyl sulfoxide (DMSO) as the solvent, the reaction temperature of trimethylsilylmethylation of tert-butylamine was lowered from 200°C used in the original synthesis to 80°C. In step 2, substituting n-butanol in place of methanol reduced the amount of oligomerization observed and increased the yield to 69%. Overall, these improvements allowed for the preparation of pyrrolidine acid 3 in 22% overall yield in 99% ee from cinnamate 39 (Scheme... 

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