ChemInform Abstract: Optimization and Scale‐Up of an Asymmetric Route to the LTB₄ Inhibitor Ontazolast.

Abstract

Optimization and Scale-Up of an Asymmetric Route to the LTB 4 Inhibitor Ontazolast.-A potential industrial process involving a telescoped series of operations is described. Inexpensive chiral auxiliary α-pinene (I) is safely and effectively oxidized under phase transfer conditions to yield keto alcohol (II), the imine of which is alkylated with nearly complete chirality transfer. Auxiliary removal is followed by enantiomeric enrichment of key amine (VII) (90% e.e.) by transformation into its tartrate (¿99 e.e.), which is then directly converted into title compound ontazolast with 52% overall yield from (II). -(ROTH, G. P.; LANDI, J. J. JUN.; SALVAGNO, A. M.; MUELLER-BOETTICHER, H.; Org. Process Res.