Chiral electrophilic “glycinal” equivalents. New synthons for optically active α-amino acids and 4-substituted 2-oxazolidinones

✍ Scribed by Hirofumi Matsunaga; Tadao Ishizuka; Takehisa Kunieda

• Book ID: 104207447
• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 973 KB
• Volume: 53
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(96)01077-0

✦ Synopsis

The thermal reaction of 3-l(IS)-2-alkoxy-l-apocamphanecarbonyl]-2-oxazolones (21a-c) with dialkyl azodicarboxylates (9) results in exclusive formation of [4 + 2] type cycloadducts (22 and 23) with moderate levels of diastereofacial selection (up to 72% d.e.). The diastereomers thus obtained were readily purified and subsequent treatment with acidic methanol followed by removal of the auxiliary with LiBH4/MeOH (1:2) gave optically pure 4-methoxy-5-hydrazino-2-oxazolidinones (26 and 27), which serve as ¢t-aminoaldehyde templates useful for the synthesis of a wide variety of optically active o~-amino acids as well as 4-alkyl and 4-aryl-2-oxazolidinones.