Johannes G. H. Willems, Marco C. Hersmis, René de Gelder, Jan M. M. Smits, Jeannet B. Hammink, F. Jan Dommerholt, Lambertus Thijs and Binne Zwanenburg
A convenient multigram ‘one pot procedure’ for
the synthesis of methyl N-tritylaziridine-2-carboxylates
1 and 2, starting from the N-tritylmethyl esters of
L-serine 9 and L-threonine 10 and using methanesulfonyl chloride
and triethylamine, is described. The
N-tritylaziridin-2-ylmethanols 3 and 4 are prepared from
the corresponding methyl
N-tritylaziridine-2-carboxylates 1 and 2 using a
Grignard reaction. 1H and 13C NMR spectral
and HPLC chromatographic analysis of aziridine alcohols 3 and 4
have been performed. The crystal structures of compounds 3 and
4 reveal that the aziridine ring substituents have the
diphenylmethanol and the trityl groups in a trans
relationship and show an intramolecular hydrogen bond between the
aziridine nitrogen and the hydroxy group. According to
temperature dependent 1H NMR spectral
analysis, a hydrogen bond is also present in solution. The
enantiomeric purity of the
N-tritylaziridin-2-ylmethanols 3 and 4 has been
determined using HPLC techniques.