Reference

Method for racemizing of R- or S-form 2-tetrahydrofuroic acid ester

Method for racemizing of R- or S-form 2-tetrahydrofuroic acid ester. Eom, Gi Nam; Lim, Jong Ho; Lim, Sang Cheol (SK Corporation, S. Korea). Repub. Korean Kongkae Taeho Kongbo KR 2002012420 A 16 Feb 2002, No pp. given (Korean). (Korea, Republic Of). 16874-33-2 is the cas registry number. This chemical is also mentioned in this article. CODEN: KRXXA7. CLASS: ICM: C07D307-12. APPLICATION: KR 2000-45701 7 Aug 2000. DOCUMENT TYPE: Patent CA Section: 27 (Heterocyclic Compounds (One Hetero Atom)) Provided is a method for racemizing of R- or S- form 2-tetrahydrofuroic acid(THFA) ester economically and effectively, thereby recycling S-form or S-form 2-THFA ester produced from manufg. of S-form or S-form 2-THFA in optical resoln. of THFA. The method for racemization comprises reacting 100 part by wt. of R-form or S-form THFA ester and 50-500 part by wt. of the formula(2) contg. 0.1-10 wt.% of alkoxy metallic salt of the formula(3) based on the R-form or S-form THFA ester, at room temp. to alc. boiling temp. for 0.5-30 h to obtain racemic THFA ester of the formula(1). In the formulas, R is 1-12 carbon numbered, linear or branched, satd. or unsatd. alkyl or aryl group; M is selected from the group consisting of Li, Na and K. .

Preparation of tetrahydrofuranthiocarboxylic acids

All Rights Reserved. Preparation of tetrahydrofuranthiocarboxylic acids. Taketsuna, Akihisa; Okai, Hideto; Nakano, Hitomi (Sakai Chemical Industry Co., Ltd.Chemical with cas number 16874-33-2 also plays role., Japan). Jpn. Kokai Tokkyo Koho JP 2006327939 A 7 Dec 2006, 7pp. (Japanese). (Japan). CODEN: JKXXAF. APPLICATION: JP 2005-149080 23 May 2005. DOCUMENT TYPE: Patent CA Section: 27 (Heterocyclic Compounds (One Hetero Atom)) R1COSH [R1 = (un)substituted tetrahydrofuranyl] are prepd. by halogenation of R1CO2H (R1 = same as above), followed by treatment with (hydro)sulfides of alkali metals and/or alk. earth metals in water and/or org. solvents. Thus, tetrahydrofuran-2-carboxylic acid was dropwise added to SOCl2, the reaction mixt. stirred at 80-85° for 5 h, dropwise added to aq. NaHS at 45-50°, and treated at 50° for 1 h to give 88.9% tetrahydrofuran-2-thiocarboxylic acid. .