Synthesis of γ-halogenated and long-chain β-hydroxy-α-amino acids and 2-amino-1,3-diols using threonine aldolases

Abstract The l - and d -threonine aldolase catalyzed formation of γ-halogenated and long-chain l - and d -3-alkylserine-derivatives 1 – 12 , respectively, was shown starting from glycine and halogenated C 2 – or C 4 –C 12 aldehydes. l TA from Pseudomonas putida accepted all tested aldehydes with strongly varying diastereoselectivity (de up to 93%). Only aldehydes smaller than decanal were converted by d TA from Alcaligenes xylosoxidans with good selectivities (de up to 73%). Utilizing isobutanal enantio- and diastereopure d - syn -2-amino-3-hydroxy-4-methylpentanoic acid was obtained (ee>99%, de>95%), which was converted to the corresponding 2-amino-1,3-diol.