STEREOSELECTIVE SYNTHESIS OF STABLE ISOTOPE-LABELED L-ALPHA-AMINO ACIDS - ELECTROPHILIC AMINATION OF OPPOLZERS ACYL SULTAMS IN THE SYNTHESIS OF L-[N-15]ALANINE, L-[N-15]VALINE, L-[N-15]LEUCINE, L-[N-15]PHENYLALANINE AND L-[1-C-13,N-15]VALINE

Using 1-chloro-1-[N-15]nitrosocyclohexane, we have prepared five L-[al pha-N-15]amino acids. The stereoselective electophillic hydroxyaminati on of (S)-acylbornane-10,2-sultams, followed by Zn-o/H+ reduction, and alkaline cleavage of the chiral auxiliary, gave the amino acids in 97 .2-99.5% e.e. By starting with labeled (S)-acylbornane-10,2-sultams th is stereoselective route could be to prepare many C-13 and/or N-15 iso topomers of alpha-amino acids.