Synthese von Azaanalogen der Ascorbinsäure und der Isoascorbinsäure

✍ Scribed by Stachel, Hans-Dietrich ;Zeitler, Klaus ;Lotter, Hermann

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 717 KB
• Volume: 1994
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.199419941113

✦ Synopsis

Synthesis of Azaanalogues of Ascorbic Acid and Isoascorbic Acid

The synthesis of the hitherto unknown azaanalogues of ascorbic acid (±)‐10b and isoascorbic acid (±)‐10a is described. The aldol‐type reaction of the tetramic acid derivative 4 with benzyloxyacetaldehyde gives rise to a mixture of the adducts (±)‐5a and (±)‐5b. By X‐ray analysis 5b proved to represent the threo isomer. Catalytic debenzylation of both adducts 5 to the glycols 9 was successful only with 5a leading to 9a. On the other hand, both isomers (±)‐9a and (±)‐9b have been obtained from the aldols 6a/6b by successive debenzylation and desilylation. Removal of the remaining protective group from 9a/9b yielded racemic N‐benzylazaisoascorbic acid and racemic N‐benzylazaascorbic acid, respectively.