65534-62-5Relevant articles and documents
Reduction of β-Hydroxy Ketones with Catecholborane. A Stereoselective Approach to the Synthesis of Syn 1,3-Diols
Evans, David A.,Hoveyda, Amir H.
, p. 5190 - 5192 (1990)
The stereoselective reduction of acyclic β-hydroxy ketones to syn 1,3-diols may be achieved with the mild reducing agent catecholborane.In certain instances reaction stereoselectivity may be enhanced through rhodium(I) catalysis.
Screening, substrate specificity and stereoselectivity of yeast strains, which reduce sterically hindered isopropyl ketones
Hiraoka, Chihiro,Matsuda, Masaaki,Suzuki, Yuya,Fujieda, Shigeo,Tomita, Mina,Fuhshuku, Ken-ichi,Obata, Rika,Nishiyama, Shigeru,Sugai, Takeshi
, p. 3358 - 3367 (2007/10/03)
Towards the synthesis of sterically hindered optically active secondary alcohol 2, yeast strains (Candida floricola IAM 13115 and Trichosporon cutaneum IAM 12206) with si-face hydride attack on isopropyl phenylsulfonylmethyl ketone 1 were developed by scr
The zirconium alkoxide-catalyzed aldol-tishchenko reaction of ketone aldols
Schneider, Christoph,Hansch, Markus,Weide, Timo
, p. 3010 - 3021 (2007/10/03)
The aldol-Tishchenko reaction of ketone aldols as enol equivalents has been developed as an efficient strategy to furnish differentiated 1,3-anti-diol monoesters in one step. The thermodynamically unstable ketone aldols undergo a facile retro-aldolization to yield a presumed zirconium enolate in situ, which then undergoes the aldol-Tishchenko reaction in typically high yields and with complete 1,3-anti diastereocontrol. Evaluation of a broad range of metal alkoxides as catalysts and optimization of the reaction protocol led to a modified zirconium alkoxide catalyst with attenuated Lewis acidity and dichloromethane as solvent, which resulted in suppression of the undesired acyl migration to a large extent. Various ketone aldols have been prepared and subjected to the general process, giving rise to a broad range of differently substituted 1,3-anti-diol monoesters, which may be hydrolyzed to the corresponding 1,3-anti-diols.
Enantioselective synthesis ofanti 1, 3-diols via ru(ii)-catalyzed hydrogénations
Blanc, Delphine,Ratovelomanana-Vidai, Virginie,Marinetti, Angela,Genêt, Jean-Pierre
, p. 480 - 482 (2007/10/03)
The homogeneous ruthenium-catalyzed hydrogénation of new symmetrical 1, 3-diketones has been achieved with various ligands including SKEWPHOS and Me-DuPHOS. Complete conversions with enantiomeric and diastereomeric excesses up to 99% were obtained. This represents a new catalytic application of the chiral ligands above. Thieme Stuttgart.
Stereocontrolled reductive amination of 3-hydroxy ketones
Haddad, Mansour,Dorbais, Jerome,Larcheveque, Marc
, p. 5981 - 5984 (2007/10/03)
syn-1,3-Aminoalcohols are synthesized in high diastereomeric excess by reductive amination of 3-hydroxyketones with sodium cyanoborohydride in the presence of benzylamine.
In search of open-chain 1,3-stereocontrol
Barbero, Asun,Blakemore, David C.,Fleming, Ian,Wesley, Robert N.
, p. 1329 - 1352 (2007/10/03)
Methylation of methyl 4-phenylpentanoate 25 gives the diastereoisomers methyl (2RS,4SR)-2-methyl-4-phenylpentanoate 26 and methyl (2RS,4RS)- 2-methyl-4-phenylpentanoate 27 in a ratio of 44:56. The aldehydes 3-dimethyl(phenyl)silylbutanal 28, 3-dimethyl(ph
Polychlorinated materials as a source of polyanionic synthons
Guijarro, Albert,Yus, Miguel
, p. 1797 - 1810 (2007/10/03)
The reaction of dichloromethane (1a) or dichlorodideuteriomethane (1b) with an excess of lithium powder (1:7 molar ratio) and a catalytic amount of DTBB (5 mol%) in the presence of a carbonyl compound 2 (1:2 molar ratio) in THF at -40°C yields, after hydrolysis, the corresponding 1,3-diols 3 in moderate yields. The process is applied to other gem-dichlorinated materials such as 7,7-dichloro [4.1.0]heptane (4), 1,1-dichlorotetramethylcyclopropane (7) and dichloromethyl methyl ether (10), using pivalaldehyde as electrophile. Starting from 1,1,1-trichlorinated compounds or tetrachloromethane (14) and using chlorotrimethylsilane as electrophile at temperatures ranging between -80 and -90°C, the corresponding polysilylated compounds 15-17 are prepared applying the mentioned methodology.
Asymmetric Synthesis of (3R,5R)- and (3S,5S)-2,6-Dimethylheptane-3,5-diol, useful C2 Chiral Auxiliaries
Jacoby, C.,Braekman, J.C.,Daloze, D.
, p. 753 - 756 (2007/10/02)
(R,R)- and (S,S)-2,6-Dimethylheptane-3,5-diol, which are useful C2 chiral auxiliaries, have been both synthesized in high optical purity from 2,6-dimethylheptane-3,5-dione, by using as key step a Sharpless kinetic resolution.
Dichloromethane as a source of the CH22-synthon: A combination of an arene-catalysed lithiation and a barbier-type reaction
Guijarro, Albert,Vus, Miguel
, p. 253 - 256 (2007/10/02)
The reaction of dichloromethane 1 with an excess of lithium powder (1:7 molar ratio) and catalytic amount of 4,4'-di-tert-butylbiphenyl (5 mol %) in the presence of a carbonyl compound 2 (1:2 molar ratio) in tetrahydrofuran at -40°C yields, after hydrolysis, the corresponding 1,3-diols 3 in moderate yields. The process can be also applied to more complicated gem-dichloro derivatives such as 7,7-dichlorobicyclo[4.1.0]heptane 6 or methyl dichloromethyl ether 9.
Chiral Organometallic Reagents, I. Stereoselective Exchange of Diastereotopic Bromine Atoms by Lithium in 1,1-Dibromo-3-(trimethylsilyloxy)alkanes
Hoffmann, Reinhard W.,Bewersdorf, Martin,Krueger, Michael,Mikolaiski, Wolfgang,Stuermer, Rainer
, p. 1243 - 1252 (2007/10/02)
Bromine-lithium exchange in 1,1-dibromo-3-(trimethylsilyloxy)alkanes 4 and 6 affords the carbenoids 8 and 14, which have been added to ketones, aldehydes, arylboronates, and silylating agents.Diastereoselectivity in the generation and trapping of the carb
