- Asymmetric synthesis of (R)- and (S)- 2-pyrrolidinemethanesulfonic acid
-
(R)- and (S)-2-Pyrrolidinemethanesulfonic acid, 3a and 3b, were synthesized from the corresponding N-Boc-2-(hydroxymethyl)-1-pyrrolidine, 6a and 6b. This asymmetric synthesis proceeds in mild conditions, with good overall yields and high enantiomeric purities (>99% ee).
- Braghiroli, Daniela,Avallone, Rossella,Di Bella, Maria
-
-
Read Online
- Synthesis and activity of endomorphin-2 and morphiceptin analogues with proline surrogates in position 2
-
The opioid agonists endomorphins (Tyr-Pro-Trp-Phe-NH2; EM1 and Tyr-Pro-Phe-Phe-NH2; EM2) and morphiceptin (Tyr-Pro-Phe-Pro-NH 2) exhibit an extremely high selectivity for μ-opioid receptor. Here a series of novel EM2 and morphiceptin analogues containing in place of the proline at position 2 the S and R residues of β-homologues of proline (HPro), of 2-pyrrolidinemethanesulphonic acid (HPrs) and of 3- pyrrolidinesulphonic acid (βPrs) have been synthesized and their binding affinity and functional activity have been investigated. The highest μ-receptor affinity is shown by [(S)βPrs2]EM2 analogue (6e) which represents the first example of a β-sulphonamido analogue in the field of opioid peptides.
- Giordano, Cesare,Sansone, Anna,Masi, Annalisa,Lucente, Gino,Punzi, Pasqualina,Mollica, Adriano,Pinnen, Francesco,Feliciani, Federica,Cacciatore, Ivana,Davis, Peg,Lai, Josephine,Ma, Shou-Wu,Porreca, Frank,Hruby, Victor
-
experimental part
p. 4594 - 4600
(2010/10/19)
-
- A versatile synthesis of various substituted taurines from vicinal amino alcohols and aziridines
-
Taurine and structurally diverse substituted taurines have been synthesized by peroxyformic acid, oxidation of the thiazolidine-2-thione intermediates generated from, vicinal amino alcohols or aziridines and carbon disulfide. The stereochemistry and mechanisms of the reactions are disscussed. The method is a salt-free and versatile route, convenient in terms of purification, and can be used to synthesize optically active substituted taurines.
- Chen, Ning,Jia, Weiyi,Xu, Jiaxi
-
experimental part
p. 5841 - 5846
(2010/03/03)
-
- Expeditious and practical synthesis of various substituted taurines from amino alcohols
-
Various substituted taurines have been synthesized expeditiously and practically in satisfactory to good yields directly from amino alcohols using a two-step, one-pot procedure, in which the amino alcohols undergo sulfuric acid esterification and subsequent sodium sulfite substitution. Treatment of amino-substituted secondary alcohols using the same procedure gave 2-substituted or 1,2-disubstituted taurines, indicating the formation of aziridines as intermediates during the substitution step. This method is one of the most efficient routes for preparing structurally diverse 2-substituted and 1,2- and 2,2-disubstituted taurines. Georg Thieme Verlag Stuttgart.
- Zhang, Wei,Wang, Boyuan,Chen, Ning,Du, Da-Ming,Xu, Jiaxi
-
p. 197 - 200
(2008/12/20)
-
- Efficient synthesis of taurine and structurally diverse substituted taurines from aziridines
-
(Chemical Equation Presented) Taurine and substituted taurines were synthesized efficiently from aziridines via ring-opening reaction with thioacetic acid, oxidation with performic acid, and hydrolysis in hydrochloric acid. The current method shows more benefit in purification and efficiency in the preparation of taurine and structurally diverse 2-substituted, 2,2-disubstituted, and 1,2-, 2,2-, and 2,N-alkylene taurines.
- Hu, Libo,Zhu, Hui,Du, Da-Ming,Xu, Jiaxi
-
p. 4543 - 4546
(2008/02/05)
-
- Synthesis and pyrolytic behaviour of thiazolidin-2-one 1,1-dioxides
-
Four examples of the chiral thiazolidin-2-one 1,1-dioxides 5 have been prepared by reaction of the appropriate amino alcohols 11 with CS2 in aqueous sodium hydroxide to give the thiazolidine-2-thiones 12, followed by oxidation with KMnO4 under phase-transfer conditions in the presence of benzoic acid, either directly or via the thiazolidin-2-ones 13. Upon flash vacuum pyrolysis (FVP) at 650°C, 5a-c decompose mainly by loss of SO2 to give an alkene and benzyl isocyanate together with other products from fragmentation of the N-benzyl group. A significant minor pathway involves net loss of CO2 and water to give the 2-phenyl-4,5-dihydrothiazoles 21 together with their aromatisation products 22 and 23. A mechanism for this new heterocyclic transformation is proposed involving initial expansion to a cyclic carbamic-sulnnic anhydride (2,1,4-oxathiazin-3-one 1-oxide). The fully assigned 13C NMR spectra are presented for 5, 12 and 13 and the 33S NMR spectrum has been obtained for 5c.
- Aitken, R. Alan,Armstrong, David P.,Galt, Ronald H. B.,Mesher, Shaun T. E.
-
p. 2139 - 2145
(2007/10/03)
-
- Bicyclic β-sultams: Synthesis from monocyclic β-aminothiols and some properties
-
The cyclamine methanethiols 7 are prepared from the corresponding alcohols 3 and oxidatively transformed by treatment with chlorine into the cyclic substituted taurinechlorides 8. Upon treatment with bases, 8 is cyclized yielding the bicyclic β-sultams 9. Some spectroscopic properties and the solvolysis of 9 are briefly discussed.
- Schwenkkraus,Otto
-
-