7425-27-6Relevant articles and documents
Preparation of useful building blocks, α-iodo- and bromoalkanols from cyclic ethers using the Dowex H+/NaX (X = I, Br) approach
Turhanen, Petri A.,Veps?l?inen, Jouko J.
, p. 15937 - 15940 (2016/02/19)
Our recently reported novel green chemistry tool was effectively used for opening cyclic ethers to produce α-iodo- and bromoalkanols. The synthesis of 4-iodobutanoic acid from γ-butyrolactone has also been described. The method is based on the use of a dried Dowex H+/NaX (X = Br, I)-system, which is effective at producing α-iodoalkanols and some α-bromoalkanols from commercially available cyclic ethers. Additionally, opening of three different crown ethers to form α-iodo(polyethylene)glycols with various chain lengths is demonstrated. Haloalkanols are important building blocks in synthetic chemistry e.g. for medicinal chemistry purposes.
Antibody-catalyzed decarboxylative oxidation of vanillylmandelic acid
Taran,Renard,Bernard,Mioskowski,Frobert,Pradelles,Grassi
, p. 3332 - 3339 (2007/10/03)
The most important industrial process for the synthesis of vanillin is performed in two steps involving an electrophilic aromatic substitution of glyoxylic acid on guaiacol followed by an oxidative decarboxylation of the intermediary α-hydroxy acids formed, thereby producing not only vanillin, but also byproducts which have to be eliminated. In the present study, we took advantage of the high specificity of catalytic antibodies to improve the synthesis of vanillin. Among 11 monoclonal antibodies elicited against the quaternary ammonium hapten H3, antibody H3-12 was found to catalyze the oxidative decarboxylation of vanillylmandelic acid (VMA), the precursor of vanillin, in the presence of sodium metaperiodate. The kinetic data of the antibody-catalyzed reaction are consistent with an ordered binding mechanism. At pH 9.0, H3-12 catalyzed the transformation of VMA into vanillin with a k(cat) of 2.70 min-1, a Michaelis-Menten constant K(a) for the binary complex of 260 μM, and a K(b) for the ternary complex of 2100 μM. The catalyzed reaction was fully inhibited by a hapten analogue with a K(i) of 10 μM. The fine specificity of anti-H3 monoclonal antibodies was determined using H3-related compounds with a competitive enzyme immunoassay. Controls demonstrating that catalytic activity is actually related to antibody binding, and mechanistic studies, are also presented.
LACTONIZATION REACTIONS OF (Ω-CARBOXYALKYL)SULFONIUM SALTS
Nakamura, Takako,Matsuyama, Haruo,Takahashi, Masaya,Kamigata, Nobumasa
, p. 59 - 66 (2007/10/02)
The intramolecular cyclizations of sulfonium salts having an ω-carboxyalkyl group were investigated for the synthesis of five- to nine-membered lactones, and five- to seven-membered lactones were obtained in good yields from S-(ω-carboxyalkyl)thiolanium salts.The scope and limitations of the synthetic utility of the reaction are indicated by this study. Key words: Lactonization reactions; (ω-carboxyalkyl)diphenylsulfonium salts; S-(ω-carboxyalkyl)thiolanium salts; medium-sized lactones; large-sized lactones; sulfur-containing lactones.
