38618-25-6Relevant academic research and scientific papers
Regiodivergent Hydroborative Ring Opening of Epoxides via Selective C-O Bond Activation
Magre, Marc,Paffenholz, Eva,Maity, Bholanath,Cavallo, Luigi,Rueping, Magnus
supporting information, p. 14286 - 14294 (2020/09/15)
A magnesium-catalyzed regiodivergent C-O bond cleavage protocol is presented. Readily available magnesium catalysts achieve the selective hydroboration of a wide range of epoxides and oxetanes yielding secondary and tertiary alcohols in excellent yields and regioselectivities. Experimental mechanistic investigations and DFT calculations provide insight into the unexpected regiodivergence and explain the different mechanisms of the C-O bond activation and product formation.
Controllable Intramolecular Unactivated C(sp3)-H Amination and Oxygenation of Carbamates
Guo, Qihang,Ren, Xiang,Lu, Zhan
supporting information, p. 880 - 884 (2019/05/16)
Dual catalyst-controlled intramolecular unactivated C(sp3)-H amination and oxygenation of carbamates merging visible-light photocatalysis and earth-abundant transition metal catalysis have been reported. Useful amino alcohol and diol derivatives could be selectively obtained from readily available tertiary alcohol derivatives. The possible mechanisms have been proposed via a 1,5-HAT process followed by Lewis acid-controlled cyclization. The nickel and zinc catalysts inhibit the formation of oxygenation and amination products, respectively. An interesting phenomenon of chirality transfer is also observed.
Novel synthesis of (4R)-4-methylpentanolide from (L)-(-)-menthol
Ishmuratov,Yakovleva,Zaripova,Botsman,Muslukhov,Tolstikov
, p. 548 - 551 (2007/10/03)
A novel synthesis of the promising optically pure chiral (4R)-4-methylpentanolide that is based on several regiospecific oxidative transformations of (4R)-2,4-dimethyl-1-(1-methylethyl)-1-cyclohexene, the product of addition of (-)-menthone and methylmagn
Cerium(III) chloride promoted addition of organometallic reagents to (-)-menthone-preparation of chiral neomenthyl derivatives
Panev, Stefan,Dimitrov, Vladimir
, p. 1517 - 1526 (2007/10/03)
The activation of (-)-menthone with anhydrous CeCl3 led to high yielding additions of different organometallic reagents. Products of exclusively equatorial-addition of the reagents were obtained; only PhMgBr yielded additionally ca. 5% of the a
Synthesis of chiral calix[n]arenes - I. A synthetic approach towards a new enantiomerically pure calix[8]arene derivative
Jauch, Johann,Schurig, Volker
, p. 169 - 172 (2007/10/03)
The first epc-synthesis of a chiral calix[8]arene starting from (-)-menthone is described. In a three step sequence a new enantiomerically pure calix[8]arene derivative is obtained in good yield.
Chiral epoxides as a source of chiral β-oxidofunctionalised organolithium compounds: Reaction with electrophiles
Bachki, Abderrazak,Foubelo, Francisco,Yus, Miguel
, p. 2997 - 3008 (2007/10/03)
The reductive opening of chiral epoxides 1, 4, 7 and 11 with lithium powder and a catalytic amount of DTBB (5 mol %) in THF at -78°C, followed by treatment with different electrophiles [Bu(t)CHO, PhCHO, (CH2)5CO, PhCOMe, CO2/su
Structure-Odor Correlation, V. - From Menthone to Shyobunone - Change of Odor with Structure
Weyerstahl, Peter,Rilk, Reiner,Marschall-Weyerstahl, Helga
, p. 89 - 101 (2007/10/02)
Derivatives of menthone (4) were prepared by substitution at C-2 or C-3 whereby increasing similarity with the shyobunones (1, 2) should be achieved.Thus, the 3,3-disubstituted ketones 5-11 were synthesized by 1,4-addition to piperitone(3).The ketones 18 and 19 substituted at C-2 were prepared via the silyl ether 15.Analogously the ketones 22-25 have been synthesized.The ketones 28 and 29 were obtained from 15 via the diketone 20 and the aldol 21. - Key compound for the synthesis of 43 and 44 as well as 1 and 2 by 1,4-addition was the known ketone 40.While preparing 40 the side products 41 and 42 have also been obtained.The olfactory properties of the substituted menthones change stepwise from the minty odor of 4 by addition of spicy and woody notes up to those of 1 and 2 which possess a fruity-earthy-woody odor.
N,S-DIMETHYL-S-PHENYLSULFOXIMINE. A REAGENT FOR THE OPTICAL RESOLUTION OF KETONES
Johnson, Carl R.,Zeller, James R.
, p. 1225 - 1234 (2007/10/02)
The addition of the α-lithio derivative of (+)- or (-)-N,S-dimethyl-S-phenylsulfoximine to selected dl-ketones was carried out at -78 deg C in tetrahydrofuran followed by acid quench at that temperature to produce mixtures of diastereomeric β-hydroxysulfoximines.The optically-active diastereomers were chromatographically separated on silica gel.The purified diastereomers were thermolyzed at ca. 130 deg to produce optically-active ketones and the optically-active sulfoximine which could be recycled.
