ISSN:
0009-2940
Schlagwort(e):
Aldol reaction
;
Chiral etiolate
;
Mandelic acid
;
Chemistry
;
Inorganic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The propionates (R)-5 and (R)-6 which are derived from the readily available chiral auxiliary reagent (R)-triphenylglycol (4) have been applied in stereoselective aldol reactions. Whereas the enolate 7 and the silyl ketene acetal 12, both generated from the ester (R)-6, display only moderate diastereoselectivity when treated with benzaldehyde, ß-hydroxyesters 8b and 16a, b are formed in diastereomeric ratios up to 95:5 (ratio of the main product to the sum of all other stereoisomers) when the propionate (R)-5 is subsequently deprotonated, transmetalated into the zirconium enolate and allowed to react with aldehydes. Alkaline hydrolysis or reduction with LiAlH4 enables the conversion of the adducts 8a and 16a
Zusätzliches Material:
3 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/cber.19941271020
Permalink