Process for the preparation of acetals and ketals of 3-amimo-5-(hydroxymethyl)-cyclopentane-1,2-diols and their derivatives and salts

摘要

Preparation of 1-amino-2,3-isopropylidenedioxy-cyclopentane derivatives (I), and/or their mirror images, optionally as salts with di- or tri-basic acids. Preparation of 1-amino-2,3-isopropylidenedioxy-cyclopentane derivatives of formula (I), and/or their mirror images, optionally as salts with di- or tri-basic acids comprises: (1) converting 2-acetyl-2-azabicyclo[2,2,1]hept-5-en-3-one (II) to (III) by cis-hydroxylation; (2) reacting (III) with R2COR3, or with 2,2,-dimethoxy-propane or -butane to form bicyclic compound (IV); (3) converting this to (V) by reductive ring opening; (4) converting (V) to its ether (VI) by reaction with dimethylsulfate, benzyl chloride or alkyl bromide or iodide; and (5) alkaline hydrolysis of (VI) or (V) to (I), which is optionally converted to its salt with a di- or tri-basic acid. R 1>hydrogen, 1-6C alkyl, 3-8C cycloalkyl or benzyl; R 2>Me and then R 3>= Et, or R 2>= hydrogen and R 3>= 1-6C alkyl or phenyl; or R 2>and R 3>are together (CH 2) n; and n : 4-6. An independent claim is also included for (III), (IV), (VI) and salts of (I) with di- or tri-basic organic acids as new compounds. [Image].