Method for producing 5-hydroxypiperidine-2-carboxylic acid
A method for producing (2S,5S)/(2R,5R)-5-hydroxypiperidine-2-carboxylic acid represented by the formula (10) below: the method including removing the protecting group from the hydroxyl group in a compound represented by formula (7) below: (wherein P represents a protecting group, R 3 represents an alkyl group containing 1 to 4 carbon atoms, and A represents an alkyl group containing 1 to 10 carbon atoms, an aryl group containing 6 to 12 carbon atoms, an alkyloxy group containing 1 to 4 carbon atoms, or an aralkyloxy group containing 7 to 20 carbon atoms) to synthesize a compound represented by formula (8) below: (wherein R 3 represents an alkyl group containing 1 to 4 carbon atoms, and A represents an alkyl group containing 1 to 10 carbon atoms, an aryl group containing 6 to 12 carbon atoms, an alkyloxy group containing 1 to 4 carbon atoms, or an aralkyloxy group containing 7 to 20 carbon atoms).
1. A method for producing a compound represented by formula (9),
wherein A represents an alkyl group containing 1 to 10 carbon atoms, an aryl group containing 6 to 12 carbon atoms, an alkyloxy group containing 1 to 4 carbon atoms, or an aralkyloxy group containing 7 to 20 carbon atoms, the method comprising
(i) removing the ether protecting group from the hydroxyl group in the compound represented by formula (7) below:
wherein P represents an ether protecting group that is resistant to basic reaction conditions, R 3 represents an alkyl group containing 1 to 4 carbon atoms, and A represents an alkyl group containing 1 to 10 carbon atoms, an aryl group containing 6 to 12 carbon atoms, an alkyloxy group containing 1 to 4 carbon atoms, or an aralkyloxy group containing 7 to 20 carbon atoms;
to synthesize the compound represented by formula (8) below:
wherein R 3 represents an alkyl group containing 1 to 4 carbon atoms, and A represents an alkyl group containing 1 to 10 carbon atoms, an aryl group containing 6 to 12 carbon atoms, an alkyloxy group containing 1 to 4 carbon atoms, or an aralkyloxy group containing 7 to 20 carbon atoms;
and
(ii) (a) in the compound (8), hydrolyzing the ester groups, allowing one of the carboxyl groups to react with the hydroxyl group to allow the lactonization, and further decarboxylating the other carboxyl group; or
(b) in the compound (8), hydrolyzing the ester groups, decarboxylating one of the carboxyl groups to form a stereoisomeric mixture of a 2-monocarboxylic acid, and then isomerizing and lactonizing the stereoisomeric mixture;
to synthesize the compound represented by the formula (9) below:
wherein A represents an alkyl group containing 1 to 10 carbon atoms, an aryl group containing 6 to 12 carbon atoms, an alkyloxy group containing 1 to 4 carbon atoms, or an aralkyloxy group containing 7 to 20 carbon atoms.
2. A compound represented by formula (9a) below:
wherein A′ represents an alkyl group containing 1 to 10 carbon atoms or an aryl group containing 6 to 12 carbon atoms.