- Practical syntheses of (S)-4-hydroxytetrahydrofuran-2-one, (S)-3-hydroxytetrahydrofuran and their (R)-enantiomers
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Optically active 4-hydroxytetrahydrofuran-2-one (3) has been synthesized in good yield from optically active ethyl 4-chloro-3-hydroxybutanoate (2) by refluxing with dilute hydrochloric acid. In a similar manner, optically active 3-hydroxytetrahydrofuran (5) was prepared from optically active 4-chloro-1,3-butanediol (4), which was derived from 2 by NaBH4 reduction. These new cyclizations proceed without racemization. VCH Verlagsgesellschaft mbH, 1997.
- Yuasa, Yoshifumi,Tsuruta, Haruki
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Read Online
- PROCESS FOR PRODUCTION OF (S)-(TETRAHYDROFURAN-3-YL)HYDRAZINE
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A process for production of (S)-(tetrahydrofuran-3-yl)hydrazine of formula I or an acid addition salt thereof, comprising hydrolysis or hydrogenation step of protected hydrazine compound of formula VII, wherein Ra is a tert-butyl group or a benzyl group, is disclosed. (S)-(Tetrahydrofuran-3-yl)hydrazine of formula I or an acid addition salt thereof is a useful intermediate in the preparation of a PDE9 inhibitor.
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Paragraph 0084
(2016/04/19)
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- Design, synthesis and properties of artificial nucleic acids from (R)-4-amino-butane-1,3-diol
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A new artificial nucleic acid analogue, (R)-Am-BuNA, was developed with a simplified acyclic (R)-4-amino-butane-1,3-diol phosphodiester backbone. Phosphoramidite monomers of (R)-Am-BuNA were incorporated into DNA oligonucleotides (ODNs) and G-quadruplexes. Their thermal stability, conformation change and biological stability were further investigated using UV-melting, circular dichroism (CD) and gel electrophoresis. The results suggested that thermal stability of the duplexes of (R)-Am-BuNA modified ODNs and their complementary ODN is highly dependent on the substitution position. Substitution of thymidine at the 7th position in a thrombin-binding DNA aptamer (TBA) results in a slight increase in Tm with no effect on quadruplex conformation on the CD spectrum in comparison to that of the natural G-quadruplex. Further enzymatic experiments with fetal bovine serum (FBS) and snake venom phosphodiesterase (SVPDE) indicated that only single replacement of a (R)-Am-BuNA modified nucleobase greatly inhibited oligonucleotide degradation, which shows their promising applications as capping nucleotides in nucleic acid drugs. This journal is
- Li, Pengfei,Sun, Jingjing,Su, Meng,Yang, Xiaogai,Tang, Xinjing
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p. 2263 - 2272
(2014/04/03)
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- PROCESS FOR THE EFFICIENT PREPARATION OF 3-HYDROXYTETRAHYDROFURAN
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Disclosed is a process for the efficient preparation of 3-hydroxytetrahydrofuran. In particular, the present invention provides a process for the preparation of 3-hydroxytetrahydrofuran by performing cyclization of 4-halo-1,3-butanediol either neat or in an organic solvent by heating to 75°C to 18O°C. In the present invention, acidic solution is not used in the cyclization and, thus, the reaction environment is improved. Further, the cyclization product 3-hydroxytetrahydrofuran is purified by a simple process. In addition, according to the present invention, chirality of the starting material is substantially maintained. Consequently, chiral 3-hydroxytetrahydrofuran with a high optical purity of 99.0% ee or better can be prepared economically, in high yield.
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Paragraph 63-64
(2008/12/07)
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- Process for preparing 3-Hydroxythiolane
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A process for preparing 3-hydroxythiolane which is characterized by reacting a compound of the following formula, ???wherein X is a halogen atom, and R2 is a substituted or unsubstituted alkyl group, substituted or unsubstituted aralkyl group, or substituted or unsubstituted aryl group, with a metal sulfide.
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Page/Page column 3
(2008/06/13)
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- Penem derivatives
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An efficient, multistep process for the synthesis of certain 6-(1-hydroxyethyl) 2-substituted penem antibiotics from 2-[4R-(triphenylmethylthio)-3S-(1R-(dimethyl-t-butylsilyloxy)ethyl)-2-azetidon-1 yl]acetic acid ester.
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- Process for optically active 3-thiolanyl sulfonate esters
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Intermediates and a stepwise process for the conversion of an alkyl 4-chloro-3R-hydroxybutyrate to optically active compounds of the formula STR1 wherein R is (C1 -C3)alkyl, phenyl or tolyl. The latter compounds are in turn useful as an intermediate in the preparation of penem antibiotic 5R,6S-6-(1R-hydroxyethyl)-2-(1R-oxo-3S-thiolanylthio)-2-penem-3-carboxylic acid and corresponding pharmaceutically acceptable salts and esters.
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- Process for optically active 3-thiolanyl sulfonate esters
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Intermediates and a stepwise process for the conversion of ethyl 4-chloro-3R-hydroxybutyrate to optically active compounds of the formula STR1 wherein R is (C1 -C3)alkyl, phenyl or tolyl. The later compounds are in turn useful as an intermediate in the preparation of penem antibiotic 5R,6S-6-(1R-hydroxyethyl)-2-(1R-oxo-3S-thiolanylthio)-2-penem-3-carboxylic acic and corresponding pharmaceutically acceptable salts and esters.
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