Medvedskaya, L. B. published the artcileStructural orientation of heterodiene synthesis during the reaction of oxazoles with acetylenic dienophiles, Name: 4,5-Dimethyloxazole, the publication is Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya (1973), 1311-15, database is CAplus.
The Hueckel approximation of MO calculation gave the energy level values and electron densities in oxazoles with H, Me, Ac, CO2R and OR in the 5-position and Me in the 4-position. The stabilization energies of probable transition states in reactions of these compounds with acetylenic dienophiles (Et propiolate or Et phenylpropiolate) were computed. The results of these calculations agreed with the general results of Diels-Alder reactions of these substances. The π-electron density in the reactants was not a satisfactory criterion for deducing the orientation of such reactions since dynamic features were important. Hence, stabilization energy or some index of reactivity that describes reactant polarizability was the more useful parameter.
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, Name: 4,5-Dimethyloxazole.
Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem