Chiral allyl cations in cycloadditions to furan: Synthesis of 2-(1'-phenylethoxy)-8-oxabicyclo[3.2.1]oct-6-en-3-one in high enantiomeric purity

Angewandte Chemie - International Edition

Volumn 37, Issue 9, 1998, Pages 1266-1268

  Stark, Christian B W ^a   Eggert, Ulrike ^a   Hoffmann, H M R ^a  

^a LEIBNIZ UNIVERSITY HANNOVER   (Germany)

Author keywords

Carbocations; Chiral auxiliaries; Cycloadditions; Medium sized rings; Polycycles; Stacking interactions

Indexed keywords

EID: 0032543083     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/(sici)1521-3773(19980518)37:9<1266::aid-anie1266>3.3.co;2-0     Document Type: Article

References (20)

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8. For the stereoselective generation and capture of a chiral and enantiopure bridgehead carbocation in biomimetic caryophyllene chemistry see C. E. Sowa, U. Eggert, H. M. R. Hoffmann, Tetrahedron 1993, 49, 4183, U. Vogt, U. Eggert, A. M. Z. Slawin, D. J. Williams, H. M. R. Hoffmann, Angew. Chem. 1990, 102, 1530; Angew. Chem. Int. Ed. Engl. 1990, 29, 1456.
9. For the stereoselective generation and capture of a chiral and enantiopure bridgehead carbocation in biomimetic caryophyllene chemistry see C. E. Sowa, U. Eggert, H. M. R. Hoffmann, Tetrahedron 1993, 49, 4183, U. Vogt, U. Eggert, A. M. Z. Slawin, D. J. Williams, H. M. R. Hoffmann, Angew. Chem. 1990, 102, 1530; Angew. Chem. Int. Ed. Engl. 1990, 29, 1456.
10. For the stereoselective generation and capture of a chiral and enantiopure bridgehead carbocation in biomimetic caryophyllene chemistry see C. E. Sowa, U. Eggert, H. M. R. Hoffmann, Tetrahedron 1993, 49, 4183, U. Vogt, U. Eggert, A. M. Z. Slawin, D. J. Williams, H. M. R. Hoffmann, Angew. Chem. 1990, 102, 1530; Angew. Chem. Int. Ed. Engl. 1990, 29, 1456.
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16. The α-ketoacetal 6 was isolated as a diastereoisomeric mixture. The compounds were not separated since the acetalic stereocenter is lost during generation of the siloxyallyl cation intermediate.
17. Less than 0.1 equivalent of TMSOTf sufficed for this transformation; cf also ref. [4].
18. With the Mosher ester of the deprotected cycloadduct (Scheme 3) and by comparison with an independently prepared sample of (-)-2-hydroxy-8-oxabicyclo[3.2.1]oct-6-en-3-one: I. C. Rose, PhD thesis, University of Hannover, 1997.
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