Salicylaldehyde based oxazolidines as catalysts for the asymmetric addition of diethylzinc to aldehydes

✍ Scribed by Raleigh W. Parrott II; Christopher G. Hamaker; Shawn R. Hitchcock

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2008
• Tongue: English
• Weight: 412 KB
• Volume: 45
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570450336

✦ Synopsis

Abstract

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A series of oxazolidines have been prepared by condensation of N‐isopropyl norephedrine with a variety of salicylaldehyde derivatives. Despite the stereochemical relationship of (1__R,2__S)‐norephedrine with (1__R__,2__S__)‐ephedrine, the resultant oxazolidines 12‐14 were determined to have a stronger stereochemical relationship with (1__S__,2__S__)‐pseudoephedrine based oxazolidines. The resultant oxazolidines were used as catalytic ligands in the addition of diethylzinc to several aldehydes. It was determined that the oxazolidine derivative 12 gave the highest yield and a moderate enantioselectivity.