| 摘要 |
The invention relates to a method for producing (2S,4R,9S)-octahydro-1H-indole-2-carboxylic acid. The invention is characterised in that a. a compound of the formula (I) (R<1>O)2CH-CH2-CH(OR<2>)2, wherein R<1> and R<2> are equal or different and represent C1-4-alkylgroups, is converted with water in the presence of an acid catalyst; b. the 3,3-dialkoxypropionaldehydes of the formula (II) (R<1>O)2CH-CH2-CHO thus obtained are subjected to a Henry reaction with nitromethane; c. the 4,4-dialkoxy-1-nitro-2-butanol of the formula (III) (R<1>O)2CH-CH2-CHOH-CH2-NO2 thus obtained is dehydrated; d. the nitroolefin IV thus obtained is converted into the corresponding trans-4-(2,2-dialkoxyethyl)-5-nitro-1-cyclohexene V by means of a Diels-Alder reaction; e. the substance V thus obtained is hydrated to form corresponding trans-4-(2,2-dialkoxyethyl)-5-amino-1-cyclohexane VI; f. the compound VI is subjected to a racemic division and the (1S,2R)-1-amino-2-(2,2-dialkoxyethyl)-cyclohexane VII is obtained in the enantiomerically pure form by enzymatic racemic division; g. the compound VII obtained thereby is hydrolised to form the corresponding acetal VIII; h. the aldehyde obtained thereby is converted into the corresponding nitrile VIII and i. said nitrile is cyclised to form the (2S,4R,9S)-octahydro-1H-indole-2-carboxylic acid.
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