Tetrahedron

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

H Matsunaga, T Ishizuka, T Kunieda

Index: Matsunaga, Hirofumi; Ishizuka, Tadao; Kunieda, Takehisa Tetrahedron, 1997 , vol. 53, # 4 p. 1275 - 1294

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Citation Number: 29

Abstract

The thermal reaction of 3-[(1S)-2-alkoxy-1-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% de). The diastereomers thus obtained were readily purified and subsequent treatment with acidic methanol followed by removal of the auxiliary with LiBH 4MeOH (1: 2) gave optically pure ...