Synthesis of thiazolo[2,3-a]pyridines from enaminoesters by tandem conjugate addition-cyclization

Tetrahedron Letters

Volumn 39, Issue 5-6, 1998, Pages 455-458

  Caballero, Esther ^a   Puebla, Pilar ^a   Medarde, Manuel ^a   Honores, Zoila ^a   Sastre, Pablo ^a   López, Jose Luis ^a   San Feliciano, Arturo ^a  

^a UNIVERSITY OF SALAMANCA   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

DIHYDROPYRIDINE DERIVATIVE; HETEROCYCLIC COMPOUND; THIAZOLO[3,2 B]PYRIDINE DERIVATIVE; UNCLASSIFIED DRUG;

ARTICLE; DRUG SYNTHESIS; REACTION ANALYSIS; STEREOCHEMISTRY; STEREOISOMERISM;

EID: 0032576813     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(97)10574-3     Document Type: Article

References (16)

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8. 13C-NMR: 1: 19.2 (q), 37.5 (t), 41.5 (t), 82.7 (d), 160.0 (s), 170.9 (s); 2: 30.8 (q), 38.4 (t), 45.7 (t), 51.1 (t), 76.0 (s), 170.6 (s).
9. 11).
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12. 11).
13. 13.-Relatives stabilities of reaction intermediates 5-hydroxy-2,3,5,6,8,8a-hexahydrooxazolo/ thiazolo[3,2-a]pyridines, analogues to those of the Hantzsch reaction (Katritzky, A.R.; Ostercamp, D.L.; Yousaf, T.I. Tetrahedron 1986, 42, 5729), and final products 2,3,8,8a-tetrahydrooxazolo/ thiazolo[3,2-a]pyridines were calculated by MM2 force field implemented in Macromodel (Mohamadyi, F.; Richards, N.G.J.; Guida, W.C.; Liskamp, R.; Lipton, M.; Caufield, C.; Chang, G.; Hendrickson, T.; Still, W.C. J. Comput. Chem. 1990, 11, 440). In all cases the most stable stereoisomers were the 7,8-trans-8,8a-cis products indicating that the thermodynamic control of the reaction would produce the same stereochemistry from enaminones of ethanolamine and thioethanolamine.
14. 13.-Relatives stabilities of reaction intermediates 5-hydroxy-2,3,5,6,8,8a-hexahydrooxazolo/ thiazolo[3,2-a]pyridines, analogues to those of the Hantzsch reaction (Katritzky, A.R.; Ostercamp, D.L.; Yousaf, T.I. Tetrahedron 1986, 42, 5729), and final products 2,3,8,8a-tetrahydrooxazolo/ thiazolo[3,2-a]pyridines were calculated by MM2 force field implemented in Macromodel (Mohamadyi, F.; Richards, N.G.J.; Guida, W.C.; Liskamp, R.; Lipton, M.; Caufield, C.; Chang, G.; Hendrickson, T.; Still, W.C. J. Comput. Chem. 1990, 11, 440). In all cases the most stable stereoisomers were the 7,8-trans-8,8a-cis products indicating that the thermodynamic control of the reaction would produce the same stereochemistry from enaminones of ethanolamine and thioethanolamine.
15. 14.-Take, K.; Okumura, K.; Takimoto K.; Ohtsuka, M.; Shiokawa, Y.; Chem. Pharm. Bull. 1992, 40, 899.
16. 15.-Kuckländer, U.; Hilgeroth, A.; Arch. Pharm. (Weinheim), 1994, 327, 287.