20013-73-4Relevant academic research and scientific papers
DEHYDROGENATION REACTION
-
Page/Page column 11-12, (2018/04/02)
The present invention relates to the field of organic synthesis and more specifically it concerns a process for the dehydrogenation of compound of formula (I) catalyzed by palladium (Pd0) in elemental metallic form.
Facile synthesis of c/s-2-alkyl-3-trialkylsilyloxycycloalkanones via the non-aldol aldol rearrangement of 2,3-epoxycycloalkanols
Jung, Michael E.,Allen, Damian A.
supporting information; experimental part, p. 2039 - 2041 (2009/04/18)
Silyl triflate-promoted rearrangement of c/s-2,3-epoxycycloalkanols A, prepared by epoxidation of the cyclic allylic alcohol and then sllylatlon, afforded good yields (~70-75%) of the c/s-2-alkyl-3-silyloxycycloalkanones B, presumably via the intermediates C and D, even with quite large α-substituents, e.g., terf-butyl. Finally, it has been shown that the stereochemistry of the epoxy alcohol is crucial as one would expect from the mechanism.
A brief and stereoselective synthesis of limonoid models, with antifeedant activity against Locusts migratoria
Fernández-Mateos,Ramos Silvo,Rubio González,Simmonds
, p. 7809 - 7816 (2007/10/03)
A short stereoselective preparation of havanensin-type limonoid models is reported. The synthesis is based on a radical domino reaction of an epoxyketone to a bicyclic hydroxyketone, and is achieved in six and nine steps from simple cyclohexenones. The epoxyhavanensin derivatives show significant antifeedant activity against Spodoptera littoralis and Spodoptera frugiperda, and the epoxyketone 21 shows potent antifeedant activity against Locusts migratoria.
Identification of a precursor to naturally occurring β-damascenone
Puglisi, Carolyn J,Elsey, Gordon M,Prager, Rolf H,Skouroumounis, George K,Sefton, Mark A
, p. 6937 - 6939 (2007/10/03)
9-Hydroxymegastigma-3,5-dien-7-yne 8a was synthesised and shown to be identical to an intermediate found in the acid-catalysed conversion of 3,5,9-trihydroxymegastigma-6,7-diene 4 to β-damascenone 1, 3-hydroxydamascone 5 and megastigma-5-en-7-yne-3,9-diol 6. When subjected to acid hydrolysis, 8a produced β-damascenone 1, in high yield. Importantly, the hydrolysate was completely free of 3-hydroxydamascone 5.
Structure-Odor Correlation, VII. - Synthesis and Olfactive Properties of Theaspirane Analogues
Weyerstahl, Peter,Buchmann, Bernd,Marschall-Weyerstahl, Helga
, p. 507 - 524 (2007/10/02)
The spirodihydrofurans 8-12 were prepared by addition of the respective alkynols to the ketone 20 (-->21-25), Lindlar hydrogenation (-->26-30), and cyclization. - The saturated derivatives 1-6 were available either by hydrogenation (8-10-->1,2,4) or via the lactol 47 and its reaction to the diols 31-36.Addition of the ethyl acetate anion to 20 (-->71), reduction (71-->73), and cyclization yielded the spirooxetane 13. - From the ynediols 76 and 77, Lindlar hydrogenation (-->78,79), cyclization (-->80,81), and further hydrogenation led to the spirotetrahydropyranes 16and 17. - Key compound for the synthesis of the ketone 18 was the geranic acid derivative 94, which could be obtained in two different ways.Cyclization of 94 to the diester 92 and Dieckmann condensation of 92 under simultaneous methylation (-->99) led to 18.The diastereoisomers 18a and b could be assigned after reduction of 18 to the separable alcohols 19a-c. - The olfactive properties (strength and quality) of the theaspirane analogues are determined by the conformational flexibility of the respective molecule.Thus, the almost rigid 13 has a very strong camphoraceous-herbaceous odor.Augmenting flexibility, particularly by increasing of the ring size (-->1,-->16), but also by alkyl substitution at C-2, results in remarkably weaker, woody-flowery notes.
THE PALLADIUM (II) ACETATE PROMOTED 6-ENDO-TRIG CYCLIZATION OF 1,1-DIALKYL-2-SILYLOXY-1,5-DIENES.
Torres, Luz E.,Larson, Gerald L.
, p. 2223 - 2226 (2007/10/02)
A route to cyclohexenones via the treatment of selected γ,δ-unsaturated enol silyl ethers with palladium (II) acetate is presented.
Oxidation of Enol Silyl Ethers: Preparation of Aeginetolide, Dihydroactinidiolide, and Actinidiolide
Rubottom, George M.,Juve, Henrik D.
, p. 422 - 425 (2007/10/02)
The preparation of the C11-terpenic lactones aeginetolide (1), dihydroactinidiolide (2), and actinidiolide (3) by using 1,3,3-trimethyl-2-(trimethylsiloxy)cyclohexene (9) as a common precursor is discussed.The key steps in the synthetic route involve the sequential m-chloroperbenzoic acid (MCPBA) oxidation and acetylation of 9 and of the siloxy diene 13 derived from 9.
Manufacture of 2,6,6-trimethyl-cyclohex-2-en-1-one
-
, (2008/06/13)
A process for the manufacture of 2,6,6-trimethyl-cyclo-hex-2-en-1-one by reacting 3-alkoxy-4-methyl-3-pentene or 3-alkoxy-4-methyl-2-pentene or a mixture of these compounds with acrolein, and reacting the resulting 2-alkoxy-2-ethyl-3,3-dimethyl-2,3-dihydro-4H-pyran with acids. The product is an intermediate for numerous syntheses of scents. Furthermore, a number of carotenoid syntheses are based on 2,6,6-trimethyl-cyclohex-2-en-1-one or its hydrogenation product, 2,6,6-trimethyl-cyclohexan-1-one.
Cycloaliphatic unsaturated ketones as odour- and taste-modifying agents
-
, (2008/06/13)
Process for the preparation of unsaturated cycloaliphatic ketones useful as perfuming and odour-modifying agents in the manufacture of perfumes and perfumed products, and as flavouring and taste-modifying agents in the aromatization of foodstuffs in general and imitation flavours for foodstuffs, beverages, animal feeds, pharmaceutical preparations and tobacco products. Compositions of matter relating to some of said unsaturated cycloaliphatic ketones which are new, and perfume- and flavouring compositions containing same.
