Combining ring-closing metathesis and hydroformylation strategies: a novel approach to spirocyclic gamma-butyrolactones.
Di- or tetrahydropyrans with a vinyl side chain are obtained by diastereoselective ring-closing metathesis or by addition of vinylmagnesium chloride to an appropriately functionalized tetrahydropyranone. The resulting allylic alcohols are converted to spirocyclic hemiacetals under hydroformylation conditions. Oxidation yields the corresponding lactones.
Schmidt
B
B
Universität Dortmund, Fachbereich Chemie, Organische Chemie, Otto-Hahn-Strasse 6, D-44227 Dortmund, Germany. bschmidt@chemie.uni-dortmund.de
Costisella
B
B
Roggenbuck
R
R
Westhus
M
M
Wildemann
H
H
Eilbracht
P
P