Methyl tiglate

Pyrolysis at 190° of the resulting diastereomeric A -pyrazolines (8) and (11) leads to elimination of nitrogen and formation of the cis- and tmns-cydo-propanecarboxylates (9) and (12), respectively. Thermal decomposition of the A -pyrazoline (13) affords methyl tiglate (14) in addition to the cyclopropane derivative (15) in a ratio 2 1, while A -pyrazolines such as (3) give only 0L,[i- or, y-unsaturated esters, and no cyclopropane derivatives. 

The hydrogenation of the esters methyl tiglate, methyl trifluorotiglate, and methyl angelate occurred slowly over 1% Pd/SiOa at room temperature and 10 bar pressure. Modification of the catalyst by cinchonidine or cinchonine induced no enantioselectivity under any conditions Typical results are given in Table 2. 

Methyl tiglate 2-Butenoic acid, 2-methyl-, methyl ester, (E)- (9) (6622-76-0)... 

Alkylation of methyl tiglate was carried out according to a reported... 

Many mechanisms had been proposed in the past to rationalize this selectivity (tri-oxanes, perepoxide, exciplex, dipolar or biradical intermediates) however, it is now generally accepted that the reaction proceeds through an intermediate exciplex which has the structural requirements of a perepoxide. This assumption is supported by (a) the lack of stereoselectivity in the reactions with chiral oxazolines and tiglic acid esters (b) the comparison of the diastereoselectivity of dialkyl substituted acrylic esters with structurally similar non-functionalized aUtenes (c) the intermolecular isotope effects in the photooxygenation of methyl tiglate and (d) the solvent effects on regioselectivity. ... 

It was proposed that, in the hydrogen abstraction step, the perepoxide opens preferentially at the C—O bond next to the unsaturated moiety. Due to the forthcoming conjugation in the adduct, the corresponding transition state is favourable, as exemplihed in the photooxygenation of methyl tiglate in Scheme 20. 

Methyl Tiglate [(E) -methyl-2-methyl-2-butenoate]. Hydroformylation of methyl tiglate leads to the following compounds ... 

Data reported in Table IV show that with this ester, the selectivity of the reaction is lower with cobalt than with rhodium as in the case of methyl tiglate. 

The results in Table VIII show that the selectivity with Co2(CO)8, although higher than that obtained with l-phenyl-2-methylpropene, is still very low. The aldehyde distribution is comparable with that for methyl tiglate. The main isomeric aldehyde is 27, and the erythro and threo diastereoisomers are formed in the same proportions. With rhodium the selectivity is very high, and the main aldehydes are 26 and 27. Twice as much threo isomer as erythro isomer is produced (14.2 and 8.4% ). 

When cobalt is used, the selectivity with aliphatic esters is higher when the a carbon is unsubstituted (methyl crotonate, methyl 3,3-dimethacrylate) than when it is substituted—e.g., methyl tiglate. 

With methyl tiglate, the extent of hydrogenolysis could be explained by the formation of a teit-alkylcobaltcarbonyl which cannot insert CO and which apparently undergoes hydrogenolysis faster than isomerization (see top of next page). 

The reactions catalyzed by rhodium are quite different from those with cobalt. For example, the results with methyl 3,3-dimethacrylate indicate a destabilizing effect of the ester group, leading mainly to hydrogenolysis since isomerization occurs less readily with rhodium than with cobalt. Moreover, the nature and the position of the substituents seem to have little influence on the alkvlrhodiumcarbonyl stability. This attenuates the effect of the ester group, as shown by the results with methyl tiglate, methyl cinnamate, and ethyl 3-phenyl-2-butenoate. 

KNH2, large excess of methyl tiglate, NH3(1), Et20, -33°C It. (24 h) different carotenoic esters and, after subsequent reactions, acids and aldehydes e.g. torularhodin (428) and retinoic acid... 

Synonyms Benzyl methyl tiglate Uses Synthetic flavoring agent, adjuvant in foods and pharmaceuticals... 

Benzyl 2-methyl propanoate Benzyl-2-methylpropionate. See Benzyl isobutyrate Benzyl methyl tiglate. See Benzyl 2,3-dimethylcrotonate... 

Carbomethoxyaniline o-Carbomethoxyaniline. See Methyl anthranilate 2-Carbomethoxy-2-butene, (E)-. See Methyl tiglate... 

Methyl-5,7-dihydroxycoumarin. See 5,7-Dihydroxy-4-methyl coumarin Methyl Di-lcinol. See Methoxydiglycol Methyl dimethylacetate. See Methyl isobutyrate Methyl trans-2,3-dimethylacrylate. See Methyl tiglate... 

Methyl (E)-2-methyl-2-butenoate Methyl trans-2-methyl-2-butenoate Methyl (E)-2-methyl-2-butenoic acid. See Methyl tiglate Methyl 2-methyl-2-butyl ether. Seet-Amyl methyl ether Methyl 2-methyl butyrate CAS 868-57-5 53955-81-0 EINECS/ELINCS 212-778-0... 

Methyl 2-methylcrotonate Methyl (E)-2-methylcrotonate. See Methyl tiglate 1-Methyl-1-(4-methyl-3-cyclohexen-1-yl) ethyl butanoate Methyl methylcyclohexenyl ethyl butrate 1-Methyl-1-(4-methyl-3-cyclohexen-1-yl) ethyl butyrate. See Terpinyl butyrate (Z)-1 -Methyl-1 -(4-methyl-3-cyclohexen-1 -yl) ethyl cinnamate. See Terpinyl cinnamate 1 -Methyl-1 -(4-methylcyclohex-3-enyl) ethyl ethanoate. See Terpinyl acetate 1-Methyl-1-(4-methylcyclohex-3-enyl) ethyl methanoate. See Terpinyl formate... 

Methyl thiram Methyl thiuramdisulfide. See Tetramethylthiuram disulfide Methyl tiglate... 

Methyl propionate 3-Methyl-5-propyl-2-cyclohexen-1-one Methyl propyl ketone Methyl tiglate Methyl p-toluate Methylundecanal dimethyl acetal Methyl 9-undecenoate Methyl 10-undecenoate Methyl valerate Methyl vanillate Musk ketone Musktibetene Myrcene Myrcenol Myrcenyl acetate Myristaldehyde Myrrh gum Myrtenol Myrtenyl acetate Myrtenyl formate Myrtle (Myrtus communis) extract Myrtle (Myrtus communis) oii P-Naphthyi isobutyl ether P-Naphthyl methyl ether Neral Nerol Neryl acetate Neryl butyrate Neryl formate Neryl isobutyrate Neryi isovaierate Neryi propionate Nona-2,4-dienai trans,trans-2,4-Nonadienal 2,6-Nonadien-1-ol... 

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