Synthesis and Anionically Induced Domino Reactions of Chiral α-Bromo α,β-Unsaturated Esters

✍ Scribed by Norbert A. Braun; Ulrike Bürkle; Martin P. Feth; Iris Klein; Dietrich Spitzner

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 342 KB
• Volume: 1998
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199808)1998:8<1569::aid-ejoc1569>3.0.co;2-w

✦ Synopsis

The chiral α-bromo α,β-unsaturated esters 3 and 9 are react with the kinetic lithium dienolates of enone 10 to give functionalized tricyclo[3.2.1.0 2,7 ]octanes 11. Esters 3 give one prepared by asymmetric Sharpless dihydroxylation (AD) of 5 and from ester 7 and the chiral diols 8 by transacetalization, single diastereomer (de Ն 95%), whereas mixtures of diastereomers (de 28 to 46%) are obtained with the esters 9. respectively. Both types of α-bromo α,β-unsaturated ester

[ * ] The term "domino reaction" instead of "tandem" or "cascade reactions" may be used for sequential reactions in one pot.

diols 6 are transformed (yield: 70Ϫ90%) into the dioxolanes