High enantio-selective process for producing pure enantiomeric cyclopentane and cyclopentene-(.beta.)-amino acids

Enantiomerically pure compounds of the general formula (V) ##STR37## in which A and L denote hydrogen or

• A and D or E and L in each together form a double bond,
• D and E are identical or different and represent hydrogen, halogen or hydroxyl or represent straight-chain or branched alkyl having up to 8 carbon atoms which is optionally mono- to disubstituted by identical or different substituents consisting of halogen, hydroxyl, phenyl, benzyloxy or carboxyl or of straight-chain or branched alkoxy, acyl or alkoxycarbonyl having in each case up to 6 carbon atoms or of a group of the formula --NR.sup.4 R.sup.5,
• in which
• R.sup.4 and R.sup.5 are identical or different and denote hydrogen, phenyl or straight-chain or branched alkyl having up to 6 carbon atoms,
• or D and E together represent a radical of the formula ##STR38## or .dbd.N--OH, in which
• R.sup.6 and R.sup.7 are identical or different and denote hydrogen or halogen or straight-chain or branched alkyl alkoxy or oxyacyl having in each case up to 8 carbon atoms, or denote benzyl or phenyl,
• or
• D and E together represent the radical of the
• R.sup.15 represents straight-chain or branched alkyl or represents alkenyl having in each case up to 5 carbon atoms, which are optionally substituted by cyano, trimethylsilyl, phenyl or trichloromethyl.

Process for the preparation of enantiomerically pure cyclopentane- and -pentene .beta.-amino acids of the general formula (I) ##STR39## in which A and L denote hydrogen

• or
• A and D or E and L in each case together form a double bond,
• D and E are identical or different and represent hydrogen, halogen or hydroxyl or represent straight-chain or branched alkyl having up to 8 carbon atoms which is optionally mono- to disubstituted by identical or different substituents consisting of halogen, hydroxyl, phenyl, benzyloxy or carboxyl or of straight-chain or branched alkoxy, acyl or alkoxycarbonyl having in each case up to 6 carbon atoms or of a group of the formula --NR.sup.4 R.sup.5,
• in which
• R.sup.4 and R.sup.5 are identical or different and denote hydrogen, phenyl or straight-chain or branched alkyl having up to 6 carbon atoms,
• or D and E together represent a radical of the formula ##STR40## or .dbd.N--OH, in which
• R.sup.6 and R.sup.7 are identical or different and denote hydrogen or halogen or straight-chain or branched alkyl, alkoxy or oxyacyl having in each case up to 8 carbon atoms, or denote benzyl or phenyl,
• or
• D and E together represent the radical of the formula .dbd.O or .dbd.S,
• R.sup.2 represents hydrogen;
• R.sup.3 represents hydrogen;
• T represents an oxygen;
• R.sup.1 represents hydrogen;
• which comprises converting meso-dicarboxylic acid anhydrides of the general formula (II) ##STR41## in which A, D, E and L have the meaning given above by an asymmetric alcoholysis with alcohols of the general formula (III)
• R.sup.15 --OH (III)
• in which
• R.sup.15 represents straight-chain or branched alkyl or represents alkenyl having in each case up to 5 carbon atoms, which are optionally substituted by cyano, trimethylsilyl, phenyl or trichloromethyl,
• and in the presence of equimolar amounts of a chiral amine base which is present in enantiomerically pure form, in inert solvents and initially via the intermediate, enantiomerically pure salt stage of the general formula (IV) ##STR42## in which A, D, E, L and R.sup.15 have the meaning given above
• and
• V represents the chiral amine base,
• to the enantiomerically pure compounds of the general formula (IVa) ##STR43## in which A, D, E, L and R.sup.15 have the meaning given above,
• subsequently, following activation of the free carboxylic acid function by reaction with liquid NH.sub.3, the enantiomerically pure amides of the general formula (V) ##STR44## in which A, D, E, L and R.sup.15 have the meaning given above,
• are prepared,
• in a further step the products are converted, by elimination of the radical R.sup.15 in inert solvents, enzymatically or in the presence of a Pd catalyst, and in each case depending on a nucleophilic auxiliary, into the compounds of the general formula (VI) or (VIa) ##STR45## in which A, D, E and L have the meaning given above,
• and
• X represents an alkali metal or alkaline earth metal atom,
• and finally a Hofmann rearrangement is carried out using alkali metal hypochlorites or alkaline earth metal hypochlorites in aqueous alkali metal hydroxide or alkaline earth metal hydroxide solution, the free amine function is initially blocked in solution with a typical amino-protecting group, which is eliminated by conventional methods after isolation of the protected compounds in accordance with conventional conditions to obtain the respective pure enantiomer.