28981-66-0Relevant academic research and scientific papers
A facile synthesis of vicinal cis-diols from olefins catalyzed by in situ generated MnxOy nanoaggregates
Dalmizrak, Di?dem,G?ksu, Haydar,Gültekin, Mehmet Serdar
, p. 20751 - 20755 (2015/03/18)
A novel protocol for the practical and green synthesis of vicinal cis-diols from 10.0 mmol olefins by using 5.0 mmol KMnO4 as oxidant and 30.0 mmol H2O2 as co-oxidant is reported. The presented procedure is easy to carry out and enables the direct transformation of linear and cyclic alkenes to the corresponding vicinal cis-diols. The synthesis of vicinal cis-diols by dihydroxylation of olefins with a KMnO4/H2O2 system was catalyzed by in situ generated MnxOy nanoaggregates. The use of H2O2 as a co-oxidant is the key for the protocol to synthesize vicinal cis-diols in high yields, because it assists the oxidation of MnxOy nanoaggregates, which have an active role in the oxidation reaction medium.
Synthesis of stereodefined substituted cycloalkenes by a one-pot catalytic boronation-allylation-metathesis sequence
Selander, Nicklas,Szabo, Kalman J.
experimental part, p. 2045 - 2051 (2009/08/10)
Stereodefined cyclohexene and cyclopentene derivatives were prepared bythe coupling of allylic alcohols and other allylic precursors with unsaturated aldehydes. These reactions are based on a multicatalytic one-pot approach involving palladium pincer complex-catalyzed boronation, allylation and ring-closing metathesis reactions. This reaction sequence can be performed in an operationally simple procedure affording the cycloalkene products in high overall yields and excellent regio- and stereoselectivities. The presented procedure has a broad synthetic scope and high functional group tolerance, which allows the synthesis of bicyclic lactone and spirane skeletons and various substitution patterns including hydroxy, silyl, vinyl, allyl, and sulfonyl groups. The studied catalytic one-pot reactions involve up to three individual processes performed by up to four acid-and transition metal-catalyzed events.
Desymmetrization of Cyclohexadienylsilanes. Regio-, Diastereo-, and Enantioselective Access to Sugar Mimics
Angelaud, Remy,Babot, Odile,Charvat, Trevor,Landais, Yannick
, p. 9613 - 9624 (2007/10/03)
Desymmetrization of cyclohexadienylsilanes available from Birch reduction of the corresponding arylsilanes is efficiently carried out using Sharpless asymmetric dihydroxylation and aminohydroxylation. Complete diastereocontrol and reasonable enantiocontrol have been attained during the preparation of the desired diols. An excellent regiocontrol has also been observed during aminohydroxylation of dienylsilanol 6b. The resulting diol 8 and hydroxycarbamate 27 have then been elaborated further, offering a straightforward access to various types of cyclitols, aminocyclitols, carbasugars, as well as the antibiotic palitantine 4. The complete functionalization of the original arylsilanes 5 is thus typically achieved in fewer than eight steps with high stereoselectivities and excellent overall yield.
Diastereospecific Hydroxyiodination of 1-Acetoxycyclohex-2-ene via Intramolecular Delivery of Oxygen
Bange, Johannes,Haughan, Alan F.,Sweeney, J. B.
, p. 1405 - 1408 (2007/10/02)
The previously unreported reaction of N-iodosuccinimide with acetoxycyclohex-2-ene to give monoacetates of 3-iodocyclohexane-1,2-diols is diastereospecific.
Catalytic One-Pot Osmylation of Cyclohexadienes: Stereochemical and Conformational Studies of the Resulting Polyols
Tschamber, Theophile,Backenstrass, Frederique,Fritz, Hans,Streith, Jacques
, p. 1052 - 1060 (2007/10/02)
Catalytic double osmylation is described for a series of cyclohexadienes in acetone/H2O in the presence of the co-oxidant N-methylmorpholine N-oxide (NMO).The formation of polyols occurred stereospecifically with cyclohexadienes 3, 7, and 11a, leading thereby to tetrols 5a, and 9a and to allo-inositol (14a), respectively.To the contrary, trans-cyclohexadiene-diol 15a gave a mixture of the stereoisomeric inositols 18a (epi), 19a (neo), and 20a (chiro).High-field NMR let to clearcut conformational analyses of the polyhydroxylated derivatives.
Efficient Syntheses of cis-6-Bromo- and cis-7-Bromo-2,2-dimethyl-3a,4,5,7a-tetrahydro-1,3-benzodioxole
Banwell, Martin G.,Lambert, John N.,Richards, Sharon L.
, p. 939 - 950 (2007/10/02)
Regio- and stereo-controlled syntheses of the title compounds (1) and (2), starting from cyclohexane-1,3-dione (10) and cyclohexa-1,3-diene (17) respectively, are reported.
Vinyl Epoxide Hydrolysis Reactions
Ross, Angela M.,Pohl, Terese M.,Piazza, Kathryn,Thomas, Michael,Fox, Bonnie,Whalen, Dale L.
, p. 1658 - 1665 (2007/10/02)
The rates of hydrolysis of cyclopentadiene oxide (3), cyclohexadiene oxide (4), cycloheptadiene oxide (5), cyclooctadiene oxide (6), butadiene oxide (7), and styrene oxide (8) have been determined as a function of pH.Each epoxide exhibited acid-catalyzed hydrolysis at low pH, and 3-5 showed significant rates for "spontaneous" reaction with solvent at intermediate pH values.The hydrolyses of several of the vinyl epoxides (4 and 5) showed kinetic terms in HO- at pH > ca. 13.Specific chloride effects attributed to nucleophilic addition of Cl- to neutral epoxide were observed for those compounds (3, 4, and 8) hydrolyzed in KCl solutions.From kinetic and product studies, mechanisms for hydrolyses of the vinyl epoxides are postulated.Acid-catalyzed hydrolyses of 3, 4, 5, and 6 were found to be A-1 in nature, proceeding via intermediate allyl cations.Product distributions depended on the structure of the cation.Mechanisms and product distributions for the spontaneous hydrolyses of vinyl epoxides were found to be variable, and dependent on the structure of the epoxide.
