Diastereoselective synthesis of methylated α-methoxy-8- oxabicyclo[3.2.1]oct-6-en-3-ones. Contrathermodynamic introduction of methoxy group by low temperature [4+3]-cycloaddition

Synlett

Volumn , Issue 2, 1999, Pages 213-215

  Pierau, S ^a   Hoffmann, H M R ^a  

^a LEIBNIZ UNIVERSITY HANNOVER   (Germany)

Author keywords

Dictyoxetane models; Kinetic control; Methoxy 2 silyloxyallyl cation intermediates; Silicon bridging; , dimethoxysilyl enol ethers

Indexed keywords

ALPHA METHOXY 8 OXABICYCLO[3.2.1]OCT 6 EN 3 ONE; UNCLASSIFIED DRUG;

ARTICLE; CHEMICAL REACTION; DIASTEREOISOMER; LOW TEMPERATURE PROCEDURES; METHYLATION; OXYGENATION; SYNTHESIS; THERMODYNAMICS;

EID: 0032935559     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-1999-2577     Document Type: Article

References (18)

1. a) Weiss, J. M.; Hoffmann, H. M. R. Tetrahedron: Asymmetry 1997, 7, ;
2. b) Nowakowski, M.; Hoffmann, H. M. R. Tetrahedron Lett. 1997, 38, 1001;
3. c) Dunkel, R.; Mentzel, M.; Hoffmann, H. M. R. Tetrahedron 1997, 53, 14929;
4. d) Lampe, T. F. J.; Hoffmann, H. M. R. J. Chem. Soc., Chem. Commun. 1996, 1931;
5. e) Lampe, T. F. J.; Hoffmann, H. M. R.; Bornscheuer, U. T. Tetrahedron: Asymmetry 1996, 7, 2889;
6. f) Lampe, T. F. J.; Hoffmann, H. M. R. Tetrahedron Lett. 1996, 37, 7695.
7. Wittenberg, J.; Beil, W.; Hoffmann, H. M. R. Tetrahedron Lett. 1998, 39, 8259; Reinecke, J.; Hoffmann, H. M. R. Chem. Eur. J. 1995, 1, 368.
8. Wittenberg, J.; Beil, W.; Hoffmann, H. M. R. Tetrahedron Lett. 1998, 39, 8259; Reinecke, J.; Hoffmann, H. M. R. Chem. Eur. J. 1995, 1, 368.
9. Chan, T. H.; Brook, M. A.; Chaly, T. Synthesis 1983, 203.
10. Murray, D. H.; Albizati, K. F. Tetrahedron Lett. 1990, 31, 4109; Föhlisch, B.; Krimmer, D.; Gehrlach, E.; Käshammer, D. Chem. Ber. 1988, 121, 1585;
11. Murray, D. H.; Albizati, K. F. Tetrahedron Lett. 1990, 31, 4109; Föhlisch, B.; Krimmer, D.; Gehrlach, E.; Käshammer, D. Chem. Ber. 1988, 121, 1585;
12. Sasaki, T.; Ishibashi, Y.; Ohno, M. Tetrahedron Lett. 1982, 23, 1693.
13. Hirsch, J. A. in Top. Stereochem.; Allinger, N. L.; Eliel, E. L. Eds.; Wiley & Sons, 1967, 199-222.
14. Hoffmann, H. M. R. Angew. Chem. 1984, 95, 29; Angew, Chem. Int. Ed. Engl. 1984, 23, 1, 15. Compact and extended are not synonymous with endo and exo. The transition state of the 6-centre Diels-Alder reaction is uniquely boat-like (cf. frozen boat-like cyclohexene moiety in norbornene, obtainable from cyclopentadiene and ethylene). Endo and exo refer to the configuration of substituents on the periphery of the newly formed 6-membered ring. Compact and extended describe alternative 7-carbon pericyclic geometries. These alternative geometries do not exist in concerted, lower-order cycloadditions such as Diels-Alder and 1,3-dipolar reactions.
15. Hoffmann, H. M. R. Angew. Chem. 1984, 95, 29; Angew, Chem. Int. Ed. Engl. 1984, 23, 1, 15. Compact and extended are not synonymous with endo and exo. The transition state of the 6-centre Diels-Alder reaction is uniquely boat-like (cf. frozen boat-like cyclohexene moiety in norbornene, obtainable from cyclopentadiene and ethylene). Endo and exo refer to the configuration of substituents on the periphery of the newly formed 6-membered ring. Compact and extended describe alternative 7-carbon pericyclic geometries. These alternative geometries do not exist in concerted, lower-order cycloadditions such as Diels-Alder and 1,3-dipolar reactions.
16. Stark, C. B. W.; Eggert, U.; Hoffmann, H. M. R. Angew. Chem. 1998, 110, 1337; Angew. Chem. Int. Ed. 1998, 37, 1266.
17. Stark, C. B. W.; Eggert, U.; Hoffmann, H. M. R. Angew. Chem. 1998, 110, 1337; Angew. Chem. Int. Ed. 1998, 37, 1266.
18. +], 153 (36), 136 (9), 125 (14), 108 (35), 100 (36), 95 (41), 86 (44), 81 (41), 72 (83), 68 (26).