Bayer Aktiengesellschaft

Wolfgang Koebernick

Paul Naab

Michael Preiss

Peter Stadler

Gunther Kinast

Wolfgang Gau

Michael Schedel

Samir Samaan

Arthur Haaf

Hans-Rolf Furtwangler

Werner Teller

The invention relates to a process for preparing 1,5-didesoxy-1,5-imino-D-glucitol (desoxynojirimicin) and N-derivative thereof, which are known to be powerful inhibitors for .alpha.-glycosidases. The process of the invention involves reducing with a complex borohydride, a 6-amino-6-desoxy-L-sorbose.

Process for the preparation of 1,5-didesoxy-1,5-imino-D-glucitol and

In the preparation of a 1,4-dihydropyridine of the formula ##STR1## in which R is a phenyl radical which is optionally substituted once or twice by nitro and/or chlorine,

Process for the preparation of 1,4-dihydropyridinedicarboxylic esters

The invention relates, inter alia, to a process for the provision of 6-amino-6-desoxy-2,3-O-isopropylidene-.alpha.-L-sorbofuranose derivatives which comprises treating a 2,3-O-isopropylidene-6-sulphonated-.alpha.-L-sorbofuranase with an amine in an aqueous medium in an autoclave, followed by reaction of the reactions product in a basic medium to provide the free amine of Formula I as described hereinafter. The invention also includes the products obtained by the reaction and the invention further includes the process for providing the compounds of Formula VII as described hereinafter by treatment of a compound of Formula I as described hereinafter with an acid, followed by hydrogenation. The products of the invention are useful as medicaments or intermediates for medicaments.

Process for the production of known and new

A process has been developed for the preparation of compounds of the formula ##STR1## wherein R is hydrogen or an optionally substituted alkyl radical, which comprises reacting glucose with a compound of the formula H.sub.2 N-R wherein R has the meaning given above to form a 1-amino-sorbitol of the formula ##STR2## wherein R has the meaning given above, reacting said 1-aminosorbitol with a compound providing a protective group which can be split off under acid conditions and is stable in the subsequent microbiological oxidation process, aerobically oxidizing the compound thus obtained microbiologically to give a protected 6-aminosorbose, splitting off the protective group under acid conditions and hydrogenating the 6-aminosorbose salt thus obtained either after being isolated or in one operation, to give the compound of the formula (I). The products obtained by the process of the invention are useful as .alpha.-glucoside inhibitors.

Production of N-substituted derivatives of 1-desoxynojirimicin

The invention relates to an improved process for the isolation and purification of aminoglycoside antibiotics of Formula (I) as defined herein combining selective lipophilization of the compound of Formula (I) in the crude product obtained by fermentation with controlled liquid/liquid extraction.

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Wuppertal, Germany

Wolfgang Koebernick