(S)-Pyroglutamic Acid, (S)-Malic Acid, and (S)-Serine as Useful Starting Materials in the Synthesis of Enantiopure Hydroxyamidines

✍ Scribed by Martin Ostendorf; Jan Dijkink; Floris P. J. T. Rutjes; Henk Hiemstra

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 398 KB
• Volume: 2000
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(200001)2000:1<115::aid-ejoc115>3.0.co;2-j

✦ Synopsis

The synthesis of four enantiopure hydroxyamidines is amidine was obtained by coupling of an (S)-malic acid derived N-acyliminium ion with β-naphthol. The other described. One amidine was obtained from (S)-pyroglutamic acid. Its key step involved the addition of phenylmagnesium amidines were obtained from an (S)-serine-derived imide which was reduced to two diastereomeric lactams that were bromide to the corresponding ester, affording the tertiary alcohol without detectable racemization. The second eventually transformed into the corresponding amidines.

nally, the enantioselectivity-inducing properties of the ami- [a] Laboratory of Organic Chemistry, Institute of Molecular the tertiary alcohol was deprotected with tetrabutylam-Chemistry, University of Amsterdam Nieuwe Achtergracht 129, NL-1018 WS