Stereoselective synthesis of unnatural spiroisoxazolinoproline-based amino acids and derivatives

J Org Chem. 2002 Aug 9;67(16):5673-7. doi: 10.1021/jo025611j.

Abstract

A route to spiroisoxazolinoproline-based amino acid derivatives is reported in which exo-methyleneprolinate 4 (tert-butyl ester) reacts as a dipolarophile with nitrile oxides to generate spiroisoxazolinoprolinates 7/10/11 in good yields (70-75%) and with ca. 1:4 cis:trans diastereoselectivity. tert-Butyl spiroisoxazolinoprolinates were separable by column chromatography and amenable to scale-up leading to single diastereoisomers of N-Boc and N-Fmoc protected spiroisoxazolinoproline amino acids.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acids / chemical synthesis*
  • Amino Acids / chemistry
  • Models, Molecular
  • Molecular Conformation
  • Oxazoles*
  • Proline / analogs & derivatives*
  • Proline / chemistry
  • Stereoisomerism
  • Structure-Activity Relationship

Substances

  • Amino Acids
  • Oxazoles
  • Proline