Synthesis, stereochemistry, and13C and1H NMR spectra of adducts of acrylic dienophiles with 5-ethoxy-2-carbethoxy-4-carbethoxymethyloxazole

Autor:	V. M. Zhulin, V. S. Bogdanov, G. V. Ostval'd, G. Ya. Kondrat'eva
Rok vydání:	1987
Předmět:	NMR spectra database chemistry.chemical_compound chemistry Diene Stereochemistry Chemical shift Substituent Alkoxy group Epimer General Chemistry Adduct Oxazole
Zdroj:	Bulletin of the Academy of Sciences of the USSR Division of Chemical Science. 36:2354-2358
ISSN:	1573-9171 0568-5230
DOI:	10.1007/bf00957314
Popis:	1. 5-Ethoxy-4-carbethoxymethyloxazole and 5-ethoxy-2-carbethoxy-4-carbethoxymethyl oxazole take part in condensations with CH2=CHX dienophiles to form 1,4-epoxy-4-ethoxy-1-(H, carbethoxy)-3-carbethoxymethylidene-exo and endo-5-X-piperidines. 2. Differences in the chemical shifts of the exo- and endo-isomers for proton H5 and carbons C1, C3, C6, and C7 unambiguously depended on the orientation of the substituent at C5. The3JH,H spin-spin coupling was also diagnostic for each of the epimers. 3. The ratio of the stereoisomeric diene adducts did not depend on the solvent used, the reaction temperature, or the pressure.
Databáze:	OpenAIRE
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