Präparative chromatographische Enantiomerentrennung von synthetisch nützlichen cyclischen Acetalen

✍ Scribed by Dieter Seebach; Stefan G. Müller; Urs Gysel; Jürg Zimmermann

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: German
• Weight: 954 KB
• Volume: 71
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19880710541

✦ Synopsis

Preparative Chromatographic Resolution of Synthetically Useful Cyclic Acetals

Racemic cyclic acetals derived from aldehydes and glycine, glycolic acid, thioglycolic acid, formylacetic acid, and acetoacetic acid (oxazolidinones 4 1 3 , dioxolanones 14,15, oxathiolanone 16, dioxinones 17-23) are resolved by preparative high-pressure liquid chromatography on silica gel coated with the polymer from N-acryloylphenylalanine ethyl ester (Chirnspher@). The separation factors a range from 1,l to 2,4. Use of a Prepbar(v-chromatography system allows injections of several grams at a time. The enantiomeric acetais thus obtained are fully characterized. First applications to amino-acid synthesis are mentioned. rac -4 rac -5 rac -6 rat -7 rac -8 rac -9 rac -10 rac-11 rac -R=H rac -1 4 rac ~ 15 lac -16 rac -3 R=CH3 rac -1 7 rac -18 rac -1 9 rac -2 0 rac -2 1 rac -2 2 rac -23 'I) Die Herstellung von und die stereoselektive Michael-Addition an rac-20 ist in einer anderen Arbeit erwahnt [45], s. auch Dissertation von J. Z., Fussnote 1.