Diastereoselective Synthesis of 2-Alkoxy-5-tert-butylmandelic Acid

Abstract

Lewis acid catalyzed addition of N-glyoxyloyl-(2R)-bornane-10,2-sultam to O-protected 4-tert-butylphenols is presented. The reactions proceed with excellent diastereoselectivities. The products of the addition are hydrolyzed with LiOH·H₂O yielding optically pure α-hydroxycarboxylic acids.

Key words

diastereoselectivity - Friedel-Crafts reactions - glyoxylate - Oppolzer’s sultam - phenols

References

• 1 Bauer T. Tarasiuk J. Tetrahedron Lett.  2002,  43:  687 
• 2a Bigi F. Sartori G. Maggi R. Cantarelli E. Galaverna G. Tetrahedron: Asymmetry  1993,  4:  2411 
• 2b Bigi F. Bocelli G. Maggi R. Sartori G. J. Org. Chem.  1999,  64:  5004 
• 3a Bauer T. Tetrahedron: Asymmetry  1996,  7:  981 
• 3b Bauer T. Tetrahedron  1997,  53:  4663 
• 4 Capet M. David F. Bertin L. Hardy J. Synth. Commun.  1995,  25:  3323 
• 5 van Walree C. Roets M. Schuddeboom W. Jenneskens L. Verhoeven J. Warman J. Kooijman H. Spek A. J. Am. Chem. Soc.  1996,  118:  8395 
• 7 Oppolzer W. Chapuis C. Bernardinelli G. Helv. Chim. Acta  1984,  67:  1397 

6

The crystal structure has been deposited at the Cambridge Crystallographic Data Centre and allocated the deposition number CCDC 215036.