used as the organochlorosilane clsi r 2 r 3 r 4 moreover an almost complete conversion can be achieved using significantly less lower alkyl lithium and dihalogenated methane the reduction of the halomethyl ketone iii is conveniently carried out in a solvent such as toluene tetrahydrofuran or an alcohol preferably methanol ethanol or isopropanol at a temperature between 30 u00b0 and 80 u00b0 c preferably 15 u00b0 c and 50 u00b0 c optionally under reduced pressure using sodium bis 2 methoxyethoxy aluminum hydride lithium aluminum hydride lithium aluminum tri tert butoxyhydride sodium borohydride tetramethylammonium borohydride or preferably using an aluminum tri alkoxide or lithium aluminum tri alkoxyhydride the term 34 alkoxide 34 embraces straight chain or branched chain saturated hydrocarbon oxides with 1 8 preferably 3 4 carbon atoms namely methyl ethyl n propyl isopropyl n butyl isobutyl sec butyl and tert butyl oxide as well as pentyl hexyl heptyl and octyl oxides the aluminum compounds can have identical or different alkoxide groups aluminum tri isopropoxide and aluminum tri sec butoxide are especially preferred compounds the reagents lithium aluminum tri tert butoxyhydride aluminum tri isopropoxide and aluminum tri sec butoxide gave unexpectedly a high stereoselectivity of 95 5 of the 1s 2s and 1s 2r isomeric halohydrins iv.