2716-23-6Relevant articles and documents
OXIDATIVE DESULFONYLATION. PHENYL VINYL SULFONE AS A KETENE SYNTHETIC EQUIVALENT
Little, R. Daniel,Myong, Sun Ok
, p. 3339 - 3342 (1980)
α-Sulfonyl carbanions undergo oxidative desulfonylation to form ketones upon treatment with molybdenum peroxide MoO5*Py*HMPA (MoOPH) in THF at -78 deg C.
NOVEL FUSED BRIDGED BICYCLIC HETEROARYL SUBSTITUTED 6-ALKYLIDENE PENEMS AS POTENT BETA-LACTAMASE INHIBITORS
-
, (2011/12/12)
A compound of formula (I) or formula (Ia) Wherein R1 , Ra, R2, X, R3 , Y1, y2, A, B and C are as defined herein. Also, pharmaceutical compositions comprising such compounds and excipients, methods of treating bacterial infections comprising administering such compounds, methods for making such compounds and hydrates of such compounds.
Thermal chemistry of bicyclo[4.2.0]oct-2-enes
Powers, David C.,Leber, Phyllis A.,Gallagher, Sarah S.,Higgs, Andrew T.,McCullough, Lynne A.,Baldwin, John E.
, p. 187 - 194 (2007/10/03)
At 300 °C, bicyclo[4.2.0]oct-2-ene (1) isomerizes to bicyclo[2.2.2]oct-2-ene (2) via a formal [1,3] sigmatropic carbon migration. Deuterium labels at C7 and C8 were employed to probe for two-centered stereomutation resulting from C1-C6 cleavage and for one-centered Stereomutation resulting from C1-C8 cleavage, respectively. In addition, deuterium labeling allowed for the elucidation of the stereochemical preference of the [1,3] migration of 1 to 2. The two possible [1,3] carbon shift outcomes reflect a slight preference for migration with inversion rather than retention of stereochemistry; the si/sr product ratio is ～1.4. One-centered stereomutation is the dominant process in the thermal manifold of 1, with lesser amounts of fragmentation and [1,3] carbon migration processes being observed. All of these observations are consistent with a long-lived, conformationally promiscuous diradical intermediate.
Thermal reactions of 7-d- and 8-d-bicyclo[4.2.0]oct-2-enes
Baldwin, John E.,Leber, Phyllis A.,Powers, David C.
, p. 10020 - 10021 (2007/10/03)
The gas phase thermal reactions exhibited by bicyclo[4.2.0]oct-2-ene and 7-d and 8-d analogues at 300 °C have been followed kinetically through GC and 2H NMR spectroscopic analyses. In contrast to the pattern of transformations exhibited by bicyclo[3.2.0]hept-2-ene and deuterium-labeled analogues, no reactions initiated by C1-C6 bond cleavage are seen, epimerization at C8 is much faster than [1,3] shifts leading to bicyclo[2.2.2]oct-2-ene, and the ratio of rate constants for [1,3] carbon migration with inversion versus migration with retention is ～1.4. Homolysis of C1-C8 to give a conformationally flexible diradical intermediate having a relatively long lifetime and multiple options for further reaction (re-formation of C1-C8 with or without net epimerization, fragmentation to 1,3-cyclohexadiene and ethylene, migration to the original C3 with inversion or retention) accords well with the observations. Clearly, orbital symmetry control does not govern stereochemistry for the [1,3] sigmatropic carbon shifts. Copyright
Activated cycloheptenone dienophiles. A versatile approach to 6,7-fused ring targets
Liu, Hsing-Jang,Yeh, Wen-Lung,Browne, Eric N. C.
, p. 1135 - 1147 (2007/10/03)
Several 2-carbalkoxy-2-cyclohepten-1-ones were prepared and their Diels-Alder characteristics examined in order to develop a facile general approach to the synthesis of cycloheptane ring-containing polycyclic natural products.Substitution pattern on the seven-membered ring was found to greatly affect the Diels-Alder behavior.In addition, some extraordinary facial stereoselectivity was observed.Key words: Diels-Alder reaction, 2-carbalkoxy-2-cyclohepten-1-ones, 6,7-fused ring system.
Selective reduction of hydroxy carbonyl to carbonyl compounds with trialkylborane/trifluoromethanesulfonic acid
Olah,Wu
, p. 407 - 408 (2007/10/02)
Triethyl- or triisopropylborane/trifluoromethanesulfonic (triflic) acid is a convenient reagent for the selective reduction of hydroxy substituted carboxylic acids, ketones and aldehydes to yield the corresponding carbonyl compounds. The scope of the reaction, experimental conditions and suggested mechanism are discussed.
Oxidations by Methyl(trifluoromethyl)dioxirane. 2. Oxyfunctionalization of Saturated Hydrocarbons
Mello, Rossella,Fiorentino, Michele,Fusco, Caterina,Curci, Ruggero
, p. 6749 - 6757 (2007/10/02)
The reaction of methyl(trifluoromethyl)dioxirane (1b), a novel dioxirane species, with two open-chain, four cyclic, and five polycyclic saturated hydrocarbons and two aralkyl hydrocarbons in CH2Cl2/1,1,1-trifluoropropanone has been studied; under mild conditions (-22 to 0 deg C), it gives alcohols and/or ketones (deriving from further oxidation of secondary alcohols) in high yields and within very short reaction times.Primary C-H bonds are not appreciably oxidized and high regioselectivities were determined for attack at tertiary over secondary C-H bonds, with theexception of norbornane, which showed opposite regioselectivity.The reaction is also highly stereoselective, since hydroxylations of cis- and trans-decalin and of cis- and trans-1,2-dimethylcyclohexane were found to be in each case stereospecific with retention.From kinetic data, Ea = 14.3 kcal mol-1 and log A = 9.9 were estimated for cyclohexane oxidation.Relative rates change in the order cyclohexane (0.78) octane (9.2) adamantane (146); cis-1,2-dimethylcyclohexane was observed to be 7-fold more reactive than its trans isomer, demonstrating remarkable discrimination for equatorial vs axial C-H attack (also noticed in the case of cis- and trans-decalin).The relative rate of oxidation of cumene vs ethylbenzene was found to be ca. 3.1 (after statistical correction), i.e., in sharp excess over values usually recorded in classical radical H-atom abstraction from benzylic position.Rate constants determined for the reactions of cumene and of ethylbenzene show the title dioxirane (1b) is more reactive than dimethyldioxirane (1a) by factors of ca. 600 and over 700, respectively.The whole of theobservations is better accommodated by an "oxenoid" mechanism, involving concerted O-atom insertion by dioxirane into C-H bonds of hydrocarbons.
Kinetics of Ozonation. 6. Polycyclic Aliphatic Hydrocarbons.
Giamalva, David H.,Church, Daniel F.,Pryor, William A.
, p. 3429 - 3432 (2007/10/02)
The reaction of ozone with norbornane, adamantane and bicyclooctane has been studied, including kinetics and product studies as well as the determination of activation paprameters for the ozonation of norbornane.This work was carried out to distinguish between hydride abstraction and a concerted insertion mechanism for the ozonation of C-H bonds.Kinetically, norbornane behaves like a secondary hydrocarbon and lacks the rate acceleration expected if a carbocation intermediate were involved in a hydride abstraction mechanism.We interpret this and other results as supporting a 1,3-dipolar insertion mechanism for the reaction of ozone with C-H bonds.
RUTHENIUM CATALYZED OXIDATION OF ALKANES
Carlsen, H. J.
, p. 19 - 24 (2007/10/02)
A ruthenium catalyzed oxidation of alkanes in CCl4-CH3CN-water is described.Product mixtures of tert. alcohols and ketones are obtained.Norbornane and bicyclooctane are oxidized to the corresponding ketones, while adamantane is transformed to 1-adamantanol.
Steric Effects on Reaction Rates - III. Application of Force-Field Calculations to Chromic Acid Oxidation of Alcohols
Mueller, Paul,Blanc, Jacky,Lenoir, Dieter
, p. 1212 - 1220 (2007/10/02)
The rates of oxidation with chromic acid of 15 bi- and polycyclic secondary alcohols have been measured and correlated with strain changes calculated by the MM1-program between the alcohols and the corresponding ketones.A correlation of the same quality is obtained upon representation of OH-strain by CH3-strain.The significance of the correlations with respect to the oxidation mechanism as well as the limitations of the applicability of force-field calculations to reactivity problems are discussed.
