Synthesis of (2S,4S,5S)-5-hydroxy-4-methylpipecolic acid via amide methylenation of 5-hydroxy-4-methyl-2-piperidinone with dimethyltitanocene

✍ Scribed by Claus Herdeis; Eberhard Heller

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 487 KB
• Volume: 8
• Category: Article
• ISSN: 0957-4166
• DOI: 10.1016/s0957-4166(97)00091-8

✦ Synopsis

4S,5S)-5-hydroxy-4-methylpiperidine-2-one 4, readily available from Sglutamic acid, serves as a starting material for the synthesis of (2S,4S,5S)-5-hydroxy-4methylpipecolic acid 12. The key step of this reaction sequence is the chemoselective methylenation of the amide carbonyl group of 6 with dimethyltitanocene to the exocyclic enecarbamate 7. Hydroboration/oxidation of the double bond resulted in the formation of