7425-27-6Relevant academic research and scientific papers
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.
5-Hydroxy[1,2]oxazinan-3-ones as potential carbapenem and D-ala-D-ala surrogates
Wolfe, Saul,Akuche, Christiana,Ro, Stephen,Wilson, Marie-Claire,Kim, Chan-Kyung,Shi, Zheng
, p. 915 - 936 (2007/10/03)
The title compounds are amino acids whose nitrogen atom is enclosed in a six-membered cyclic hydroxamate bearing a C5-hydroxyl group. They belong to a proposed new family of antibacterial agents targeted to the penicillin receptor. The glycine and alanine members of the family have been synthesized, as racemates, in seven steps from the four-carbon synthon diketene and the tert-butyl esters of N-hydroxyglycine and N-hydroxyalanine. Numerous alternatives to diketene have also been examined, but these lead mainly to five-membered cyclic hydroxamates. The theoretical considerations that have led to this synthetic programme are discussed in some detail. They include analysis of the structures of natural and unnatural penicillin surrogates, analysis of the penicillin pharmacophore, and a treatment of the chemical reaction with which penicillin blocks bacterial cell wall synthesis. The glycine derivative exhibits marginal but real activity vs. Micrococcus luteus. The alanine derivative, which more closely resembles D-ala-D-ala, is fifty times more active. Two five-membered structural isomers of the glycine derivative are inactive.
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.
Synthesis of saturated fatty acids 11C (13C)-labelled in the ω-methyl position
Neu, Henrik,Kihlberg, Tor,Langstroem, Bengt
, p. 509 - 524 (2007/10/03)
A method for the preparation of saturated fatty acids 11C (13C)-labelled in the ω-methyl position is described. A highly reactive zerovalent copper complex was prepared from lithium naphtalenide reduced lithium(2-thienyl)iodocuprate. The labelling precursors were obtained by addition of tert-butyl ω-iodocarboxylates to the organocuprate and these were reacted with [11C]methyl iodide to form 11C-labelled, protected intermediates. The tert-butyl ester protecting group was rapidly removed with trifluoroacetic acid, affording fatty acids 11C-labelled in the ω-methyl position. A solid phase extraction method was developed and preceded final HPLC purification. In a typical run starting with 2.75 GBq of [11C]methyl iodide, 375 MBq (66%) [16-11C]palmitic acid was obtained within 46 min from the end of radionuclide production.
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.
Reactions of hydriodic acid with aldonolactones and n-alkanolactones. Interconversions between lactones and iodocarboxylic acids
Liu, Zhengchun,Granata, Alessandro,Shen, Xinhua,Perlin, Arthur S.
, p. 2081 - 2088 (2007/10/02)
Aldonolactones containing from four to eight carbon atoms, and lactones of the related monohydroxy-n-alkanoic acids, were subjected to reaction with 57 percent hydriodic acid at 125 deg C.As in the classical studies of Kiliani, the reduction of D-glycero-D-ido-heptono-1,4-lactone yielded mainly γ-heptanolactone.Analogously, the corresponding γ-alkanolactones were obtained as major products from the 1,4-lactones of the D-xylono, D-allono-, and D-erythro-L-talo-octono configuration.Monoiodo-n-alkanoic acids were also formed in admixture with the lactones in all of these reactions.D-Erythrono-1,4-lactone was unique among the aldonolactones in that it led only to an acid, i.e., 3-iodo-n-butanoic acid.The latter was also the product of the non-reductive reaction of hydriodic acid with β-butyrolactone whereas, by contrast, γ-butyrolactone afforded 4-iodobutanoic acid.Among compounds in the five to eight carbon series, it was found that under conditions close to equilibrium the ratio of lactone to iodoacid decreased progressively with the length of the carbon chain; e.g., in the 4 h reactions of γ-valero, γ-capro, γ-heptano,- and γ-octanolactone, the ratios were 2.4, 1.2, 0.2, and 0.1, respectively.An accompanying characteristic of these reactions is a progression in the number of isomeric iodoacids formed.Whereas γ-valerolactone was accompanied by 4-iodopentanoic acid, there were two isomers (4- and 5-) of iodohexanoic acid, three monoiodo- (including 6-iodo-) heptanoic acids, and four (including 7-iodo-) octanoic acids.In all instances, the isomer substituted at the penultimate carbon was major.An interplay of several individual reactions, including ring-opening displacements, eliminations-additions, and rearrangements, as well as a probable influence of entropy changes on the lactone-acid equilibria, appear to account largely for these observations.
AN EFFICIENT CLEAVAGE OF LACTONES WITH BORON TRIIODIDE-N,N-DIETHYLANILINE COMPLEX
Narayana, C.,Reddy, N. K.,Kabalka, G. W.
, p. 6854 - 6856 (2007/10/02)
Boron triiodide-N,N-diethylaniline complex efficiently cleaves lactones to the corresponding ω-iodocarboxylic acids and esters which are isolated in good yields.
Synthetic Methods and Reactions. 112. Synthetic Transformations with Trichloromethylsilane/Sodium Iodide Reagent
Olah, George A.,Husain, Altaf,Singh, Brij P.,Mehrotra, Ashok K.
, p. 3667 - 3672 (2007/10/02)
A new, convenient, and inexpensive alternative to the in situ equivalent of iodotrimethylsilane was developed.A mixture of trichloromethylsilane/sodium iodide in dry acetonitrile is found to be a more selective reagent than chlorotrimethylsilane/sodium iodide for the cleavage of ethers, esters, and lactones.Ethers are cleaved regioselectively by this reagent.Cleavage of esters and lactones also occured more readily with the present system.Conversion of alcohols, particularly tertiary and benzylic alcohols, to corresponding iodides is achieved in very short times at ambient temperatures.Deoxygenation of sulfoxides to sulfides is found to be instantaneous.Reductive dehalogenation of alicyclic α-halo ketones to the corresponding ketones has also been studied.The reagent is also used for the deprotection of acetals to carbonyl compounds.
CONVERSION OF OLEFINS INTO γ-BUTYROLACTONES
Brown, Stephen P.,Bal, Balkrishna S.,Pinnick, Harold W.
, p. 4891 - 4894 (2007/10/02)
Cyclopropyl esters derived from olefins undergo ring opening with iodotrimethylsilane and, after base treatment, γ-butyrolactones are obtained.
