- Synthesis and odor of optically active rose oxide
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Stereoselective synthesis of optically active rose oxide (1) by KHSO4 and Pd-BINAP-catalyzed cyclization of (3R)- and (3S)-3,7-dimethyl-6,7-octadien-1-ol (5) is described. One-pot synthesis of the (3R)- and (3S)-allenyl alcohol 5 from (3R)- and (3S)-citronellol (2) (98% ee) is also described. Furthermore, the odor properties of the four diastereomers of 1 are reported.
- Yamamoto, Takeshi,Matsuda, Hiroyuki,Utsumi, Yasuhide,Hagiwara, Toshimitsu,Kanisawa, Tsuneyoshi
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Read Online
- A method for preparing cis- rose ether (by machine translation)
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The invention discloses a preparation method of cis-rose oxide. The preparation method comprises the following steps: performing epoxidation, epoxy rearrangement and selective oxidation on citronellol serving as a starting material, and preparing allene by using a benzenesulfonohydrazine intermediate; and cyclizing the allene under an acid condition to obtain the cis-rose oxide. By adopting the preparation method, the defects of low yield, use of various toxic reagents and metal reagents, difficulty in operating in a reaction process and the like in the conventional synthesis route are overcome, meanwhile the reaction stereoselectivity is improved, and synthesis of the cis-rose oxide can be realized. In particular, the using amount of aluminum isopropoxide is reduced; acetone, p-benzoquinone and the like are taken as oxidants, so that the production cost can be lowered effectively, greater convenience is brought to application, and industrial large-scale production is facilitated; and meanwhile reactions in a plurality of steps are performed in the same reaction kettle in a one-pot reaction way, so that the reaction process is simplified greatly, the production cost is lowered, and industrial production is facilitated.
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Paragraph 0033; 0040; 0041; 0047
(2017/01/26)
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- Aluminium triflate catalysed cyclisation of unsaturated alcohols: novel synthesis of rose oxide and analogues
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Aluminium trifluoromethanesulfonate was used as an efficient catalyst for the cycloisomerisation of several unsaturated alcohols into cyclic ethers such as rose oxide and some of its ether analogues.
- Coulombel, Lydie,Weiwer, Michel,Dunach, Elisabet
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experimental part
p. 5788 - 5795
(2010/03/03)
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- Structure elucidation, enantioselective analysis, and biogenesis of nerol oxide in Pelargonium species
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A novel enantioselective synthesis of nerol oxide (3,6-dihydro-4-methyl- 2-(2-methyl-1-propenyl)2H-pyran) was used for the determination of the absolute configuration at C-2. The order of elution of the enantiomers on octakis-(2,3-di-O-butyryl-6-O-tert-butyldimethylsilyl)-γ-cyclodextrin in OV 1701-vi as the chiral stationary phase in enantioselective GC was determined as (2R) before (2S). Enantioselective multidimensional GC/MS (enantio- MDGC/MS) was used for the determination of the enantiomeric ratios of nerol oxide in different geranium oils. As a result, in all investigated oils nerol oxide occurs as a racemate. The biogenesis of nerol oxide in Pelargonium species was investigated by feeding experiments using deuterium-labeled neryl glucoside as the precursor. The Pelargonium plants were able to convert the fed precursor into racemic nerol oxide, which has to be considered as a 'natural racemate'.
- Wuest, Matthias,Reindl, Juergen,Fuchs, Sabine,Beck, Thomas,Mosandl, Armin
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p. 3145 - 3150
(2007/10/03)
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- Process for producing a rose oxide
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An improved process for production of an isomer mixture of Z- and E-2-?2-Methyl-prop-1-en-1-yl-!-4-methyl-tetrahydropyran, more commonly known under the name cis- and trans-rose oxide, which as a rule contains at least 80% of the natural Z-isomers (cis-rose oxide) which are valuable in the perfume industry.
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- SYNTHESES OF TETRAHYDROPYRANS BY PPh3/CBr4 INDUCED CYCLIZATION OF ACETALS : APPLICATION TO A SYNTESIS OF ROSE OXIDE
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Substituted tetrahydropyrans are prepared in good yields by PPh3/CBr4 induced cyclization of acetals.The utility of this new procedure is illustrated by the synthesis of cis-2-(methyl-1 propenyl)-4 methyltetrahydropyran (rose oxide).
- Wagner, A.,Heitz, M.-P.,Mioskowski, C.
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p. 1971 - 1974
(2007/10/02)
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- Convenient Synthesis of Disubstituted Cyclic Ethers. Syntheses of (-)-cis-Rose Oxide and (cis-6-Methyltetrahydropyran-2-yl)acetic Acid
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Disubstituted cyclic ethers are stereoselectively prepared on the successive treatment of δ- or ε-lactones with t-butyldimethylsiloxy-1-ethoxyethene and silyl nucleophiles in the presence of a catalytic amount of trityl hexachloroantimonate or a catalyst system of antimony pentachloride, chlorotrimethylsilane and tin(II) iodide.The present procedure is effectively applied to short syntheses of (-)-cis-rose oxide and (cis-6-methyltetrahydropyran-2-yl)acetic acid, a constituent of civet.
- Homma, Koichi,Mukaiyama, Teruaki
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p. 893 - 896
(2007/10/02)
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- 173. β-Cleavage of Bis(homoallylic) Potassium Alkoxides. Preparation of 3-Hydroxypropyl and 4-Hydroxybutyl Propenyl Ketones from γ- and δ-Lactones. Synthesis of (+/-)-Rose Oxide
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Starting from γ- and δ-lactones 1-3, a two-step preparation of 3-hydroxypropyl and 4-hydroxybutyl propenyl ketones 10-18 is described, involving as the key step the β-cleavage of the bis(homoallylic) potassium alkoxides 4a-9a.This novel methodology is illustrated by a short synthesis of (+/-)-rose oxide (20).
- Snowden, Roger L.,Linder, Simon M.,Muller, Bernard L.,Schulte, Karl H.
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p. 1879 - 1885
(2007/10/02)
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- Electrooxidative Cleavage of Carbon-Carbon Linkages. 1. Preparation of Acylic Oxoalkanoates from 2-Hydroxy- and 2-Acetoxy-1-cycloalkanones and Cycloalkanone Enol Acetates
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A methodology is described for the synthesis of acyclic oxoalkanoates 2 by electrooxidative cleavage of carbon-carbon linkages of 2-oxocycloalkan-1-ols 1 and cycloalkanone enol acetates 3.The electrolysis of 1 was carried out in a MeOH-LiClO4-(Pt) system at a constant applied voltage of 20 V by using a divided cell, giving 2 in 82-97 percent yields.On the other hand, 3 was electrolyzed in MeOH-AcOH (10:1)-LiClO4-(Pt) at 2-8 deg to give 2 in 72-79 percent yields.Electrolysis of 4-hydroxy-p-menth-8-ene afforded methyl (3R)-3,7-dimethyl-6-oxo-7-octenoate, a chiral synthetic block for the synthesis of (+)-rose oxide, in 84 percent yield.Similarly, the procedure could be applied to the preparation of methyl(+)-6-oxo-6,7-dihydrocitronellate from (+)-menthone enol acetate (74 percent) as well as 4-hydroxy-p-menthone (94 percent).Other lithium salts, i.e., LiBF4 and CF3CO2Li, can be used for the present purpose, but there are some difficulties in producing 2 with Et4NOTs and Et4NClO4.A plausible mechanism of the formation of 2 from 1 is also discussed.
- Torii, Sigeru,Inokuchi, Tsutomu,Oi, Ryu
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