1.4- Cyclohexadiene-3-carboxylate, ethyl

In the same work, the authors performed reactions in open vessel systems, either in the absence of solvent or on silica gel support in dry media . The cycloaddition of ethyl 1,3-cyclohexadiene carboxylate 81 to ethyl propiolate 82 was improved compared with the harsh classical conditions (benzene at 320 °C for 24 h) (Scheme 11.22). No specific microwave effects were observed in this reaction this was in accordance with results from ah initio calculations which indicated a synchronous mechanism with similar polarity (dipole moment) in both ground and transition states. 

Ethyl 2,6,6,trimethyl-l,3-cyclohexadiene-l-carboxylate [35044-59-8, the commercial quality also contains the a.- [25044-57-6] and 7-isomers isomers [35044-58-7]... 

Emulsion polymerization with the chain transfer agent l-benzyl-2,5-cyclohexadiene-1-carboxylic acid was also used to prepare poly(ethyl acrylate-co-methacrylic acid). Poly(N-vinylpyrrolidone) was prepared using the chain transfer agent l-i-propyl-2,5-cyclohexadiene-1 -carboxylic acid. 

OC18H29N, 2,4-di(tert-butyl)-6-(terr-butylimino)qumone, 35 94 OC18H31N, 2,4-di(tert-butyl)-6-(rert-butylamino)phenol, 35 93 02C6H9N2Br, 4,5-diaminocatechol hydrobromide, 33 115 O2C8H12N2, l,2-dimethoxy-4,5-diaminobenzene, 33 115 O2C9H12, ethyl l,4-cyclohexadiene-3-carboxylate, 35 161 O2C11H18, (llf)-2-... 

Ethano-bridged phthalate ester 56 was obtained by the DA reaction in good yield and was converted to the BCOD-fiised triester 57a, the t-butyl ester group of which was removed by treatment with TFA (Scheme 15.10) [63]. The DA reaction of tosylacetylene (5a) and 2-methoxy-l,3-cyclohexadiene proceeded smoothly to afford a diastereomeric mixture (5 1) of bicyclo[2.2.2]octenone 58 in 73% yield after hydrolysis by silica gel [64]. Diastereomeric 58 was quantitatively converted to dithiolane, which was subject to the ring expansion reaction with tellurium tetrachloride [65]. Dihydro-1,4-dithiin 59 was obtained in 74% yield. The Barton-Zard reaction of 59 with ethyl isocyanoacetate afforded pyrrole-carboxylate 60a (77% yield), which was transformed to both a-hydroxymethylpyrrole 60b and a-firee pyrrole 60c in good yields. 

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