title: Synthesis and coupling reactions of alpha,alpha-dialkylated amino acids with nucleobase side chains.
abstract: Several di- and tripeptides containing protected purine (adenine) and pyrimidine (thymine) residues on their side chains were synthesized. The parent amino acids alpha, alpha-dialkylated in a symmetrical manner. An effective coupling procedure was developed for these sterically hindered amino acids: the fluoren-9-ylmethyloxycarbonyl-protected amino acid was dehydrated to its oxazolinone form, which was coupled in good yields with amino esters in hot tetrachloroethane.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge 02139, USA.
authors.forename: I
authors.initials: I
authors.lastname: Azumaya
authors.forename: R
authors.initials: R
authors.lastname: Aebi
authors.forename: S
authors.initials: S
authors.lastname: Kubik
authors.forename: J
authors.initials: J
authors.lastname: Rebek
mesh_terms: D000225:Adenine / Q000737:chemistry*; D000478:Alkylation; D000596:Amino Acids / Q000737:chemistry*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D010081:Oxazolone; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013941:Thymine / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D007202:Indicators and Reagents; D010081:Oxazolone; D000225:Adenine; D013941:Thymine