13211-15-9Relevant articles and documents
A ONE-FLASK MULTICOMPONENT ANNULATION REACTION AS THE KEY STEP IN A TOTAL SYNTHESIS OF SPIROBICYCLIC (+/-)-β-VETIVONE
Posner, Gary H.,Shulman-Roskes, Ellen M.
, p. 4677 - 4686 (1992)
One flask, 3-component Michael-Michael-Dieckmann cyclizations are applied to 2+2+2 construction of spirobicyclic cyclohexanone β-keto esters 7 and 11 as pivotal intermediates for synthesis of naturally-occuring spirodecane β-vetivone (1).Some unexpected difficulties were encountered and are discussed.A novel BF3-promoted unidirectional dehydration of tertiary alcohol silyl ether 15 exclusively into isopropylidene cyclopentane 16 is reported.
Intramolecular Electron Transfer Reactions Catalyzed by α-Oxo and β-Oxo Substituents in the 1-Chlorobicycloheptane System
Lukach, Andres E.,Morris, David G.,Santiago, Ana N.,Rossi, Roberto A.
, p. 1000 - 1004 (1995)
Efficient intramolecular ET catalysis in SRN1 reactions was observed when a carbonyl group is present in 1-chlorobicycloheptane in the α or β position. 1-Chloro-3,3-dimethyl-2-oxobicycloheptane (1) and 4-chloro-1,7,7-trimethyl-2-oxobicycloheptane (4) reacted with diphenylphosphide ion (Ph2P(1-)) as nucleophile in liquid ammonia under photostimulation to give the substitution products in good yields, together with very small amounts of the reduction product.The substitution products were not observed in dark conditions, and the photostimulated reactions were inhibited by p-dinitrobenzene.These reactions are proposed to proceed via the SRN1 mechanism.In competition experiments, the reactivity ratio of 1 to 4 was 2.8, whereas the ratio of 1-chloro-3,3-dimethyl-2-oxobicyclooctane (8) to 4 was 1:1.On the other hand, 1-chloro-2-methylene-3,3-dimethylbicycloheptane (7) was unreactive under these experimental conditions.It then seems to follow that when there is a carbonyl group in these bicyclic compounds, in the α or β position, they react by the SRN1 mechanism, and the overall reactivity is similar, but when the C=O is replaced by a C=C, the substrate did not react in these experimental conditions.These results are in agreement with MO calculations, in which the LUMO of compounds 1, 4, and 8 belongs to the ?* MO of the C=O group, with similar energies, and is lower than the ?* MO of 7.
Enantiomer-differentiating Hydrogen Transfer from Fenchol to Menthone over Molten Indium Ctalyst
Sugawara, Hiroshi,Ogino, Yoshisada
, p. 1079 - 1086 (1982)
The inital rate (r0) of the hydrogen-transfer reaction from D-fenchol to menthone has been found to obey the following eqation r0,j = kjpA where k is the rate constant, pA is the partial pressure of D-fenchol, and the subscript j denotes any one of the optical isomers (L-, D- and D,L-) of menthone.The reaction is enantiomer-differentiating: kL > kD, and the optical resolution of D,L-menthone takes place in the reaction between D-fenchol and D,L-menthone.The experimental results are explained on the bases of an Eley-Rideal-type mechanism and stereochemically consistent transition-state models.Probable adsorption models for menthone are also proposed.
A new synthesis and preliminary evaluation of some analogues of mecamylamine-a compound with anti-addiction properties
Mangan, David,McNabola, Neasa,Clark, Emily H.,Bermudez, Isabel,Wonnacott, Susan,Southern, J. Mike
, p. 10787 - 10798 (2016/12/06)
A new synthesis of mecamylamine-a known anti-hypertensive drug with anti-addictive properties is described. The new route allowed access to two novel analogues whose activity at two nicotinic acetylcholine receptor subtypes was assessed.
Ozonides of mono-, bi- and tricyclic terpenes
Griesbaum, Karl,Hilss, Michael,Bosch, Joachim
, p. 14813 - 14826 (2007/10/03)
Ozonolysis of (+)-limonene (1) afforded a monoozonide 2 by attack of ozone at the internal double bond and two diastereomeric diozonides (3). Ozonolysis of 1 on polyethylene gave diozonides 3, and ozonolysis on silica gel gave an epoxy ozonide 5. Ozonolyses of (-)-β-pinene (15), (+)-sabinene (20) and (+)-aromadendrene (23) gave two diastereomers, each, of the corresponding ozonides 16, 21 and 24, respectively. Ozonolysis of camphene (26) gave a very labile ozonide 27, while ozonolysis of (-)-α-pinene (12) gave no ozonide. Ozonolysis of (+)-limonene (1) in the presence of formaldehyde gave a cross-ozonide (4), derived from ozone cleavage of the internal double bond, and ozonolysis of (-)-β-pinene in the presence of acetaldehyde also gave a cross-ozonide (17).
Thermochemical Studies of Carbonyl Reactions. 4. Enthalpies of Hydrolysis of Norbornyl Ketals
Wiberg, Kenneth B.,Cunningham, Wells C.
, p. 679 - 684 (2007/10/02)
The dimethyl ketals of norbornanone and of eight methyl-substituted norbornanones were prepared, and the enthalpies of hydrolysis were determined.The compounds were chosen to provide a variety of steric interactions between the methyl substituents and the ketal group, much of which would be relieved on going to the ketone.The enthalpies of reaction varied by over 4 kcal/mol.The experimental data were modeled by molecular mechanics (MM2), and although a good correlation was found for the less substituted compounds, the ketal of camphor fell off the slope = 1 correlation line.The free energy changes were determined, and were found not to be well correlated with the enthalpy changes.
Metal-catalyzed Oxidation of Camphene
Sethi, Shantic C.,Natu, Arun D.,Wadia, Murzban S.
, p. 974 - 980 (2007/10/02)
The cobalt naphthenate-catalyzed autoxidation of camphene (1) has been investigated with a view to studying the effects, on autoxidation, of (i) the absence of an easily abstractable allylic hydrogen, and (ii) the presence of an exocyclic double bond.As expected, the only reaction observed is the addition of oxygen to the double bond leading to (a) epoxide formation and (b) cleavage of carbon-carbon double bond giving rise to camphenilone (2).Formation of 2 as well as camphene epoxide (3) has been rationalized and stereochemistry of the epoxide formed has been established.The method is simlpe and synthetically useful for the preparation of camphenilone.
Halogenated Terpenoids. XXI. Concerning endo-2-Chloro-2,3,3-trimethylbicycloheptane (endo-2-Chloro-2,3,3-trimethylnorbornane: endo-Chlorocamphane)
Brecknell, Douglas J.,Carman, Raymond M.,Greenfield, Kay L.
, p. 1075 - 1080 (2007/10/02)
The stability of the title compound is discussed and attempts to synthesize it are described.
Unusual Reactivity of Strained Bridgehead Derivatives
Martinez, Antonio Garcia,Fraile, Amelia Garcia
, p. 3518 - 3520 (2007/10/02)
The solvolysis of 7,7-dimethyl-1,exo-2-bis(trifluoromethylsulfonyloxy)norbornane (5) in Et2O/I2Mg and 80percent MeOH proceeds with formation of substituted 2-norbornyl cations, yielding 1,exo-2-diiodo-7,7-dimethylnorbornane (9) and camphenilone (13), respectively.When the vic-diiode 9 is treated with LiAlH4/C6H6 partial epimerization to 1,endo-2-diiodo-7,7-dimethylnorbornane (12) is observed without reduction; this result is probably due to steric hindrance of the reactants.
Photochemical Oxidation of Thioketones: Steric and Electronic Aspects
Ramnath, N.,Ramesh, V.,Ramamurthy, V.
, p. 214 - 222 (2007/10/02)
Oxidation of diaryl, aryl alkyl, and dialkyl thioketones by singlet oxygen generated via self-sensitization and other independent methods yielded the corresponding ketone and sulfine in varying amounts.A zwitterionic/diradical intermediate arising out of the primary interaction of singlet oxygen with the thiocarbonyl chromophore is believed to be the common intermediate for the ketone and sulfine.While closure of the zwitterion/diradical to give 1,2,3-dioxathietane would lead to the ketone, competing oxygen elimination is believed to lead to the sulfine.This partitioning is governed by steric and electronic factors operating on the zwitterionic/diradical intermediate.
