7505-94-4Relevant academic research and scientific papers
Chemistry of the S=O Bond 8-A Stereochemical Investigation of Some Methyl-Substituted Trimethylene Sulphites (1,3,2-Dioxathian 2-oxides) via (13)C Nuclear Magnetic resonance
Hellier, Desmond G.,Phillips, Andrew M.
, p. 178 - 184 (1982)
(13)C NMR chemical shifts for trimethylene sulphite and 35 derivatives are presented.From the magnitudes of the β shifts it has been possible to establish chemical shift additivity relationships for a series of compounds.The results are discussed in terms of probable conformations in solution.
Total Synthesis of the Potent HIF-1 Inhibitory Antitumor Natural Product, (8R)-Mycothiazole, via Baldwin-Lee CsF/CuI sp3-sp2-Stille Cross-Coupling. Confirmation of the Crews Reassignment
Wang, Liping,Hale, Karl J.
supporting information, p. 4200 - 4203 (2015/09/15)
A convenient asymmetric total synthesis of the potent HIF-1 inhibitory antitumor natural product, (-)- or (+)-(8R)-mycothiazole (1), is described. Not only does our synthesis confirm the 2006 structural reassignment made by Crews (Crews, P., et al. J. Nat
The rhodium-catalyzed carbene cyclization cycloaddition cascade reaction of vinylsulfonates
Shi, Bairu,Merten, Sandra,Wong, David K. Y.,Chu, John C. K.,Liu, Lok Lok,Lam, Sze Kui,J?ger, Anne,Wong, Wing-Tak,Chiu, Pauline,Metz, Peter
supporting information; experimental part, p. 3128 - 3132 (2010/04/24)
Vinylsulfonates have proved to be excellent dipolarophiles for carbonyl ylides derived from diazoketones in rhodium-catalyzed intramolecular cycloadditions. Polyfunctional substrates, such as 8 and (+)-15, were readily available from hydroxy esters, e.g. 1 and the cyclopenta-1,3-dione 10, respectively, and the resulting polycyclic sultones were formed under mild reaction conditions in high yields with very good diastereoselectivities. A ruthenium-catalyzed asymmetric transfer hydrogenation was found to desymmetrize the meso-cyclopenta-1,3-dione 12 efficiently.
Boron Trifluoride Promoted Aldol Reaction of Silyl Ketene Acetals with the Intermediate Generated by the DIBALH Reduction of Carboxylic Acid Esters
Kiyooka, Syun-ichi,Shirouchi, Masashi
, p. 1 - 2 (2007/10/02)
The intermediate generated by the DIBALH reduction of carboxylic acid esters undergoes a boron trifluoride promoted aldol reaction with silyl ketene acetals to afford the corresponding β-hydroxy carboxylic acid esters in good yield.
Process for asymmetrically reducing carbonyl compounds
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, (2008/06/13)
There is disclosed a process for asymmetrically reducing a carbonyl compound, which comprises reducing the carbonyl compound by the use of a reducing agent comprising (i) an optically active tartaric acid or ester thereof and (ii) a metal borohydride, thereby producing an optically active hydroxyl compound. The process can be used for the production of optically active hydroxyesters and alcohols from ketoesters and ketones. These products are useful for the production of medicaments and liquid crystals.
Hydrocarbonylating Cyclization of Dienes, 5. - Model Experiments for the Synthesis of the Acorane Skeleton from Substituted 1,4-Dienes
Eilbracht, Peter,Acker, Michael,Rosenstock, Bernd
, p. 151 - 158 (2007/10/02)
Heading towards the generation of the five-membered ring substitution pattern in the acorane skeleton (1) the hydrocarbonylating cyclization of various substituted 1,4-dienes 3 to cyclopentanones 4 and 5 was studied.While octacarbonyldicobalt as catalyst precurser nearly exclusively leads to linking of the less substituted carbon centers, the more active (cyclooctadiene)rhodium complex also effects the formation of new quaternary centers.The 1,5-dienes 15a-e converted under the same conditions revealed no tendency to isomerize to 1,4-dienes with the same carbon skeleton or to form analogous cyclization products.Finally, using the model substrate 3i the regio- and stereoselective synthesis of the cyclopentanone system 4i containing the same substitution pattern as the five-membered ring of the target molecule 1 can be accomplished. - Keywords: Carbonylation of 1,4-dienes / Catalysis, cobalt / Catalysis, rhodium / Cyclopentanone derivatives
General Synthesis of Ketones from Carboxylic Esters and Carboxamides by Use of Mixed Organolithium-Magnesium Reagents: Syntheses of Artemisia Ketone
Fehr, Charles,Galindo, Jose,Perret, Roland
, p. 1745 - 1752 (2007/10/02)
The novel reagents formed by combination of Grignard reagents (RMgX) with lithium diisopropylamide (LDA) convert non-enolizable carboxylic esters or carboxamides into ketones which are protected from further reaction by their in situ conversion into enolates.These enolates can be trapped with electrophiles such as Me3SiCl and allyl bromide.The scope of this Grignard mono-addition is illustrated by two direct synthesis of artemisia ketone (14).
NMR Spectroscopic Studies of Intermediary Metabolites of Cyclophosphamide. 2. Direct Observation, Characterization, and Reactivity Studies of Iminocyclophosphamide and Related Species
Boyd, Victoria L.,Summers, Michael F.,Ludeman, Susan Marie,Egan, William,Zon, Gerald,Regan, Judith B.
, p. 366 - 374 (2007/10/02)
4-Hydroxy-5,5-dimethylcyclophosphamide (6) was synthesized as a stable (to fragmentation) analogue of 4-hydroxycyclophosphamide (1).In anhydrous Me2SO-d6 (0.03 mol percent water), cis- and trans-6 were observed by multinuclear NMR spectroscopy to equlibrate with α,α-dimethylaldophosphamide (7) and 5,5-dimethyliminocyclophosphamide (8).Identification of 8 was based on 1H, 13C, and 31P chemical shifts, selective INEPT and two-dimensional NMR correlation experiments, and temperature-dependent equilibria data.The interconversion of cis-/trans-6 and -7 was also observed in lutidine buffer; 8 was not detected under the aqueous conditions.In Me2SO-d6, hydroxy metabolite 1 underwent dehydration to give iminocyclophosphamide (5), as evidenced by chemical shift data and a selective INEPT experiment.Concentrations of cis-/trans-1, aldophosphamide (2), and 5 were found to be temperature-dependent with higher temperatures favoring 2 and 5 in a reversible manner, thus indicating that 1/2/5 were interconverting.The addition of small amount of water to Me2SO-d6 solutions of imine 5 resulted in the immediate disappearance of its NMR signals.The role of imine 5 in the conversion of 1 to C-4 substituted analogues of 1 was elucidated for the formation of 4-cyanocyclophosphamide (3a) from 1 and sodium cyanate in lutidine buffer.
α-Oxo Sulfones. 4. Correction of a Pretended α-Oxo Sulfone by an Unambiguous Synthesis of the Revised Structure
Schank, K.,Frisch, A.,Zwanenburg, B.
, p. 4580 - 4582 (2007/10/02)
By an independent synthesis the oxidation product of 1,1-dichloro-2,2-dimethyl-1-(phenylthio)-3-butene (1) was shown not to be α-oxo sulfone "2" as published earlier but a phenylsulfonyl γ-butyrolactone, 3.This synthesis involves the intramolecular reaction of a sulfenic carboxylic mixed anhydride with an olefinic bond.A rationale for the formation of 3 from 1 is presented.
