5019-82-9Relevant academic research and scientific papers
Organoleptic Compounds
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, (2009/07/03)
The present invention is directed to the fragrance compounds and their intermediates and a method of improving, enhancing or modifying a fragrance formulation through the addition of an olfactory acceptable amount wherein the dotted line represents a possible single or double bond; wherein R is equal to a C3-C7 hydrocarbon moieties R1 and R2 together can be selected from the group consisting of oxygen and may form a closed ring structure represented by
Ring expansions of 2-haloethynyl-2-norbornanols
Djuardi, Elsa,Bovonsombat, Pakorn,Mc Nelis, Edward
, p. 11793 - 11802 (2007/10/02)
2-Haloethynyl-2-norbornanols react with iodine and Koser's reagent in acetonitrile to afford two ring-expanded products, 2-[(Z)-haloiodomethylidene]bicyclo[3.2.1]octan-3-one and 3-[(Z)-haloiodomethylidene]bicyclo[3.2.1]octan-2-one. These results contrast with the 2-haloethynyl-2-bornanols which lead to the corresponding 3-octanones.
Corner Attack on exo- and endo-Tricyclo2,4>octane by Deuteron and Mercuric Ions
Coxon, James M.,Steel, Peter J.,Whittington, Barry I.,Battiste, Merle A.
, p. 1383 - 1391 (2007/10/02)
Reaction of endo-tricyclo2,4>octane (1) with deuteron in methanol-d1 gave a mixture (62:38) of methoxy ethers 3b and 4b from cleavage of the most substituted cyclopropane bond.The reaction proceeds by attack of deuterium at the corner of the cyclopropane.Trapping of the intermediate cation 5b is competitive with rearrangement to the nonclassical cation 6b.Reaction of exo-tricyclo2,4>octane (2) under similar conditions gave methoxy ether 11b, which results from rupture of an external cyclopropyl bond, and methoxy ether 12b formed from rapture of the internal cyclopropyl bond with inversion at the site of both electrophilic and nucleophilic attack.Reaction of hydrocarbon 1 with mercuric acetate in methanol gave 4-endo-(acetoxymercurio)-2-endo-methoxybicyclooctane (3c) from attack of the mercuric ion at the corner of the cyclopropane and nucleophilic attack by methanol with inversion without molecular rearrangement.Similar reaction of the exo hydrocarbon 2 gave product 12c from internal bond rupture without molecular rearrangement and with inversion of configuration at the site of electrophilic and nucleophilic attack.In addition an almost equal quantity of 11c, a product of rupture of the external cyclopropyl bond, was formed.The stereochemistry of mercuric ion and deuteron attack at C2 at the corner of the cyclopropane ring of 1 and 2 is rationalized by consideration of the symmetry and energy of the molecular orbitals involved.
DEAMINATION OF BICYCLOOCTAN-2-YL- AND BICYCLOOCTAN-2-YL-AMINES. EVIDENCE FOR CLASSICAL PRECURSORS OF NON-CLASSICAL CARBONIUM IONS
Maskill, Howard,Wilson, Alan A.
, p. 119 - 128 (2007/10/02)
Bicyclo octan-2-yl- and exo-bicyclooctan-2-yl-amines have been deaminated in acetic acid by nitrous acid and via their N-phenyltriazenes; their ethyl N-nitrosocarbamates have also been solvolysed in ethanol.Product distributions by a given method from the structurally isomeric starting materials are similar to each other and to common product distribution obtained from bicyclooctan-2-yl and exo-bicyclooctan-2-yl toluene-p-sulphonates.Each amine gives, however, a small but unmistakable excess of the structurally unrearranged product compared (in the case of subtitution) with the distribution obtained from the solvolysis of the corresponding bicyclo-octyl toluene-p-sulphonates. endo-Bicyclooctan-2-ylamine has also been deaminated in acetic acid by nitrous acid and via its ethyl N-nitrosocarbamate in ethanol.The prouct ratios of these reactions are characteristically different from those of the isomric amines but, as far as substitution is concerned, are similar to what is obtained from endo-bicyclooctan-2-yl toluene -p-sulphonate.A common mechanism describes all the deaminative reactions.We propose that classical carbonium ions are the initial products of fragmentation of diazo-intermediates.These are intercepted to only a small extent to give products structurally and stereochemically characteristic of the original amines; to an even smaller extent they rearrange to isomeric classical carbonium ions, which in turn may be intercepted.The predominant reaction of the initially formed classical carbonium ions is rearrangement to non-classical isomers.From both becyclooctan-2-yl- and exo-bicyclooctan-2-yl-amines, the same unsymmetrical nonclassical carbonium ion is produced as has been implicated in the solvolysis of the corresponding toluene-p-sulphonates. endo-Bicyclooctan-2-ylamine deamination gives rise to an isomeric symmetrical non-classical carbonium ion, the same one that intervenes in the solvolysis of endo-bicyclo-octan-2-yl toluene-p-sulphonate.Symmetrical and unsymmetrical non-classical carbonium ions once formed give product ratios largely independent of their origins or modes of formation although the symmetrical one appears to undergo a small extent of isomerization to the (more stable) unsymmetrical species.These results are contrasted with those obtained from simple carbocyclic systems (without branching at the β-carbon) in which deamination and toluene-p-sulphonate solvolysis give characteristically different and unrelated product distributions.
SILICON IN SYTHESIS-17 CHLROMETHYL(TRIMETHYLSILYL)LITHIUM-A NEW REAGENT FOR THE DIRECT CONVERSION OF ALDEHYDES AND KETONES INTO α,β-EPOXYTRIMETHYLSILANES
Burford, Clifford,Cooke, Frank,Roy, Glenn,Magnus, Philip
, p. 867 - 876 (2007/10/02)
Treatment of chloromethyltrimethylsilane 1 with sec-BuLi at -78 deg produces chloromethyl(trimethylsilyl)lithium 4.Treatment of 4 with a wide range of aldehydes and ketones gives α,β-epoxytrimethylsilanes 5-28, which on acidic hydrolysis give homologated aldehydes.
RING EXPANSION OF KETONES TO 1,2-KETO-THIOKETALS
Knapp, Spencer,Trope, Adrea F.,Ornaf, Raphael M.
, p. 4301 - 4304 (2007/10/02)
Treatment of cyclic ketones with (MeS)3C-Li, then CuClO4.4CH3CN, gives the corresponding ring expanded 1,2-keto-thioketals.
A new preparative ring expansion for bicyclic ketones. Homoketonization of cyclopropoxide analogs
Hoyano, Yumiko,Patel Vijay,Stothers, J. B.
, p. 2730 - 2732 (2007/10/02)
Homoketonization of some readily prepared cyclopropoxides affords a new synthetic method for ring expansion of the and ring systems.
