Regioselective Reactions of Ethyl (4,5-Dihydrofuran-3-yl)-2-oxoacetate and Ethyl 2-(3,4-Dihydro-2H-pyran-6-yl)-2-oxoacetate with 1-Unsubstituted Aminoazoles

• Published in: Synthesis (Stuttgart) 2012-03, Vol.44 (6), p.895-902
• Main Authors: Stepaniuk, Oleksandr O., Matvienko, Vitalii O., Kondratov, Ivan S., Shishkin, Oleg V., Volochnyuk, Dmitriy M., Mykhailiuk, Pavel K., Tolmachev, Andrei A.
• Format: Article
• Language: English
• Subjects: Chemistry; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with o, s, se, te hetero atom and condensed derivatives; Heterocyclic compounds with only one n hetero atom and condensed derivatives; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Organic chemistry; Preparations and properties
• ISSN: 0039-7881; 1437-210X
• DOI: 10.1055/s-0031-1289733

Abstract The reactions of ethyl (4,5-dihydrofuran-3-yl)-2-oxo­acetate and ethyl 2-(3,4-dihydro-2H-pyran-6-yl)-2-oxoacetate, as 1,3-bielectrophiles, with N-unsubstituted 5-aminoazoles, as N-C-N-binucleophiles, are the subject of this work. Regioselective heterocyclizations of ethyl 2-(3,4-dihydro-2H-pyran-6-yl)-2-oxoacetate lead to 3-hydroxypropyl-7-ethoxycarbonyl substituted pyrazolo[1,5-A]pyrimidines and triazolo[1,5-A]pyrimidines whilst the corresponding reactions of ethyl (4,5-dihydrofuran-3-yl)-2-oxoacetate result in the formation of oxodihydropyrano[4,3-E] annulated products.