Enzymatic resolution of syn-2-azido-1,3,4-trihydroxybutane catalysed by lipases in the transesterification mode

The enzymatic resolution of both syn-2-azido-1,3,4-trihydroxybutane 1 and s yn-2-azido-1,4-diacetoxy-3-hydroxybutane 2 have been undertaken with differ ent lipases as catalysts and vinyl acetate as acylating agent. Lipases Aman o PS and Amano AK proved to be the superior catalysts for this resolution. Indeed, both enantiomers of 1 are easily available in good yields and very good e.e.s (up to >99%). The use of chiral HPLC with a Chiralcel OD-H colum n allowed the determination of e.e.s of both diacetate 2 and triacetate 3 ( syn-2-azido-1,3,4-triacetoxybutane) in a single analysis and thus facilitat ed the precise control of the reaction. (C) 2000 Elsevier Science Ltd. All rights reserved.