Synthesis and anionically induced domino reactions of chiral α-bromo α,β-unsaturated esters

Publikations-Art

Zeitschriftenbeitrag

Autoren

Braun, N. A.; Buerkle, U.; Feth, M.P.; Klein, I.; Spitzner, D.

Erscheinungsjahr

1998

Veröffentlicht in

European Journal of Organic Chemistry

Band/Volume

8/

Seite (von - bis)

1569-1576

The chiral α-bromo α,β -unsatd. esters I (R = H, Me, Ph) and II (R = Ph, PhCH₂OCH₂) are prepd. by asym. Sharpless dihydroxylation and by trans-acetalization, resp. Both esters react with the kinetic Li dienolates of 3-methyl- or 3-methoxy-2-cyclohexenone to give functionalized tricyclo[3.2.1.02,7]octanes. Esters I give 1 single diastereomer (≤ 95% de), whereas mixts. of diastereomers (28-46% de) are obtained with II.