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Title:
METHOD OF CONVERTING BOROXAZOLIDONE INTO CORRESPONDING &agr -AMINO ACID BY RING OPENING WITH PROTECTIVE-GROUP ELIMINATION
Document Type and Number:
WIPO Patent Application WO/2004/020392
Kind Code:
A1
Abstract:
Conversion of a boroxazolidone, a 5-membered cyclic compound derived from an &agr -amino acid, into an &agr -amino acid by an entirely new ring-opening reaction (Umezawa reaction). (I) → (II) (In the formulae, R and R' each means optionally substituted alkyl or aryl.) The reaction is a novel and effective ring opening/protective-group elimination reaction by which a boroxazolidone can be easily converted to a corresponding compound (&agr -amino acid) under milder conditions at a high conversion.

Inventors:
Umezawa, Takashi (3-25-10-301, Kamitoda Toda-shi, Saitama, 335-0022, JP)
Application Number:
PCT/JP2003/010879
Publication Date:
March 11, 2004
Filing Date:
August 27, 2003
Export Citation:
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Assignee:
Umezawa, Takashi (3-25-10-301, Kamitoda Toda-shi, Saitama, 335-0022, JP)
International Classes:
C07H15/04; C07B51/00; C07C227/12; C07C227/18; C07C229/22; (IPC1-7): C07C229/22; C07B51/00; C07C227/12
Other References:
DENT W.H. ET AL.: '9-BBN: An amino acid protecting group for functionalization of amino acid side chains in organic solvents' ORGANIC LETTERS vol. 4, no. 8, 18 April 2002, pages 1249 - 1251, XP002976351
WANG J. ET AL.: 'Synthesis of omega-tert-butyl esters of aspartic acid and glutamic acid via B,B-difluoroboroxazolidones' CHEMICAL & PHARMACEUTICAL BULLETIN vol. 44, no. 11, 1996, pages 2189 - 2191, XP002976352
ACHER F. ET AL.: 'Resolution and regioselective protection of glutamic acid analogues. I. Resolution of diastereomeric alpha-boroxazolidone derivatives' TETRAHEDRON ASYMMETRY vol. 5, no. 4, 1994, pages 731 - 744, XP002061590
GARCIA M. ET AL.: 'Efficient method for the preparation of (S)-5-hydroxynorvaline' TETRAHEDRON ASYMMETRY vol. 11, 2000, pages 991 - 994, XP002958934
NEFKENS G.H.L. ET AL.: 'Boroxazolidones as simultaneous protection of the amino and carboxyl group in alpha-amino acids' TETRAHEDRON vol. 39, no. 18, 1983, pages 2995 - 2998, XP002976353
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