公开(公告)号：JP2000319271A

公开(公告)日：2000-11-21

申请号：JP2000124500

申请日：2000-04-25

Applicant: BASF AG

Inventor： BOETTCHER ANDREAS ,  GURSKI HANS ,  KUNTZE THOMAS ,  KJAERGAARD KARSTEN

IPC: C07B61/00 ,  C07D307/62

Abstract: PROBLEM TO BE SOLVED: To provide a method for producing L-ascorbic acid representing no drawbacks involved in the corresponding conventional technology. SOLUTION: This method for producing L-ascorbic acid comprises lactonization of a solution containing a 2-keto-L-gulonic acid-3-10C alkyl ester under an acidic condition; wherein the lactonization is preferably carried out in an inert solvent immiscible with water in the presence of a mineral acid; alternatively, it is preferable that, the lactonization is carried out in a halocarbon in the presence of aqueous hydrochloric acid; in this case, the halocarbon as inert solvent to be used is selected from the group consisting of dichloromethane, chloroform and perchloroethylene.

公开(公告)号：DE19919203A1

公开(公告)日：2000-11-02

申请号：DE19919203

申请日：1999-04-28

Applicant: BASF AG

Inventor： BOETTCHER ANDREAS ,  GURSKI HANS ,  KUNTZE THOMAS ,  KJAERGAARD KARSTEN

IPC: C07B61/00 ,  C07D307/62

Abstract: Preparation of L-ascorbic acid (I) involves lactonizing a melt of 2-keto-L-gulonic acid 3-10C alkyl ester (II) under acid conditions.