501085-84-3Relevant academic research and scientific papers
New optically active 2H-azirin-3-amines as synthons for enantiomerically pure 2,2-disubstituted glycines: Synthesis of synthons for Tyr(2Me) and Dopa(2Me), and their incorporation into dipeptides
Brun, Kathrin A.,Linden, Anthony,Heimgartner, Heinz
, p. 3422 - 3443 (2007/10/03)
The synthesis of novel unsymmetrically 2,2-disubstituted 2H-azirin-3-amines with chiral auxiliary amino groups is described. Chromatographic separation of the mixture of diastereoisomers yielded (1′R,2S)-2a,b and (1′R.2R)-2a,b (c.f. Scheme 1 and Table 1), which are synthons for (S)- and (R)-2-methyltyrosine and 2-methyl-3′,4′-dihydroxyphenylalanine. Another new synthon 2c, i.e., a synthon for 2-(azidomethyl)alanine, was prepared but could not be separated into its pure diastereoisomers. The reaction of 2 with thiobenzoic acid, benzoic acid, and the amino acid Fmoc-Val-OH yielded the monothiodiamides 11, the diamides 12 (cf. Scheme 3 and Table 3), and the dipeptides 13 (cf. Scheme 4 and Table 4), respectively. From 13, each protecting group was removed selectively under standard conditions (cf. Schemes 5-7 and Tables 5-6). The configuration at C(2) of the amino acid derivatives (1R,1′R)-11a, (1R,1′R)-11b, (1S,1′R)-12b, and (1R,1′R)-12b was determined by X-ray crystallography relative to the known configuration of the chiral auxiliary group.
