Process For Preparing (r Or S)-2-alkyl-3-heterocyclyl-1-propanols

Abstract

Compounds of the formula (I) in which R'<SUB>1</SUB>, R'<SUB>2</SUB>,R'<SUB>3 </SUB>and Het are each defined as specified in the description are obtainable in high yields by a stereoselective addition of R'<SUB>3</SUB>-substituted propionic esters onto R'<SUB>1</SUB>- and R'<SUB>2</SUB>-substituted unsaturated, bicyclic heterocyclylaldehydes of the formula R-CHO to give corresponding 3-(R)-3-hydroxy-2-R'<SUB>3</SUB>-propionic esters. Conversion of the OH group to a leaving group, a subsequent regioselective elimination to give 3-(R)-2-R'<SUB>3</SUB>-propenoic esters, followed by: 1) hydrolysis to the corresponding 3-(R)-2-R'<SUB>3</SUB>-propenoic acids, their enantioselective hydrogenation to corresponding chiral 3-(R)-2-R'<SUB>3</SUB>-propenoic acids and their reduction, or 2) hydrolysis to the corresponding 3-(R)-2-R'<SUB>3</SUB>-propenoic acids, their reduction to corresponding 3-(R)-2-R'<SUB>3</SUB>-allylalcohols and their enantioselective hydrogenation, or 3) reduction to corresponding 3-(R)-2-R'<SUB>3</SUB>-allylalcohols and their enantioselective hydrogenation, where R is formula (II) and the enantioselective hydrogenations are performed with metal complexes which have, as ligands, ferrocene-1,1'-diphosphines which have, in the 1-position, a ferrocene-substituted secondary phosphine group and, in the1'-position, a secondary phosphine group.


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