Basf Aktiengesellschaft

Fritz Naeumann

Wolfgang Hoelderich

Rolf Hartmuth Fischer

Franz Merger

Rudolf Kummer

Matthias Schwarzmann

Werner Bertleff

Werner Steck

Heinz-Walter Schneider

Harald Rust

Eckhard Hickmann

Heinrich Aichinger

Uwe Vagt

Helmut Lermer

5-Methylbutyrolactone is prepared by a process in which a pentenoic ester of the formula I

Preparation of 5-methylbutyrolactone

The present invention relates to a method for producing optically active alcohol derivatives, which are useful as fungicides, herbicides or plant growth regulators, represented by the formula, ##STR1## by carrying out the asymmetric reduction of a ketone compound represented by the formula, ##STR2## with a boron hydride-reducing agent modified with an optically active amino alcohol represented by the formula, ##STR3## and also relates to the boron hydride type compound obtained by reacting the above optically active amino alcohol with a boron hydride compound and its production method.

Preparation of alkenecarboxylic esters

Benzyl ketones of the general formula I ##STR1## where R.sup.1 is C.sub.1 -C.sub.8 -alkyl which is unsubstituted or substituted by cycloalkyl or aryl and R.sup.2 and R.sup.3 are each halogen, C.sub.1 -C.sub.4 -alkyl, hydroxyl, C.sub.1 -C.sub.4 -alkoxy or C.sub.2 -C.sub.4 -methylenedioxy, are prepared by a process in which a glycol monoether of the general formula II ##STR2## where R.sup.1, R.sup.2 and R.sup.3 have the abovementioned meanings and R.sup.4 is C.sub.1 -C.sub.8 -alkyl, is converted in the presence of silica, a phosphate or a zeolite at from 50.degree. to 500.degree. C. and under from 0.01 to 50 bar.

Preparation of benzyl ketones

A process for the separation of ortho-, meta- and para-tolunitrile from ternary mixtures of isomers entails removing ortho-tolunitrile from these mixtures by distillation under pressures of from 10.sup.2 and 10.sup.5 Pa and with a reflux ratio of from 1:1 to 200:1, and distilling the remaining binary mixture of meta- and para-tolunitrile to concentrate to more than 75 mol-% para-tolunitrile, and freezing out the paratolunitrile at below 26.degree. C., and a process for the preparation of suitable ternary mixtures of isomers entails isomerization of pure ortho-, meta- or para-tolunitrile or mixtures thereof at from 380.degree. to 580.degree. C. on zeolite catalysts.

Separation of ortho-, meta- and para-tolunitrile from ternary mixtures

In an improved process for preparing 4-pentenates by isomerization, where isomeric pentenates are treated at elevated temperatures with zeolites and 4-pentenates are distilled out of the reaction mixture, the improvement comprises using pentenates in mixture with alkanols.

Preparation of 4-pentenates

Pentenoic esters are prepared by heating formylvaleric esters at from 50.degree. to 400.degree. C. in the presence of zeolites or one or more phosphates selected from the group consisting of aluminum phosphate, silicon aluminum phosphate, boron aluminum phosphate, silicon iron aluminum phosphate, cerium phosphate, zirconium phosphate, boron phosphate, iron phosphate and strontium phosphate.

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Mannheim, Germany

Fritz Naeumann