108146-96-9Relevant academic research and scientific papers
Asymmetric solution-phase mixture aldol reaction using oligomeric ethylene glycol tagged chiral oxazolidinones
Turkyilmaz, Serhan,Wilcox, Craig S.
, p. 2031 - 2033 (2017)
Sorting tags are oligomeric structures that can be used as protecting groups or chiral auxiliaries enabling solution-phase mixture syntheses of multiple tagged compounds in one pot and allowing for facile and predictable chromatographic separation of products at the end of synthetic sequences. Perfluorinated hydrocarbon and oligomeric ethylene glycol (OEG) derivatives are known classes of sorting tags. Herein we describe the preparation of OEGylated chiral oxazolidinones and their use in asymmetric solution-phase mixture aldol reactions. Through the use of such oxazolidinones based on tyrosine four different individually tagged aldol adducts were obtained as a mixture, chromatographically demixed, detagged, and it was shown that these processes gave the desired aldol products in good yield and enantioselectivity.
MONOFLUORINATION STEREOSELECTIVE PAR LE PHENYLTETRAFLUOROPHOSPHORANE (PhPF4) PART. II. APPLICATION A LA SYNTHESE DES ISOMERES threo ET erythro DES ALKYL-2 FLUORO PHENYLPROPANOATES DE METHYLE. ANALYSE CONFORMATIONNELLE PAR R.M.N. DE 19F et 1H
Ayi, A. I.,Remli, M.,Guedj, R.
, p. 127 - 144 (1981)
The stereoselective fluorination of four couples of diastereoisomeric 2-alkyl 3-hydroxy 3-phenylpropanoic methyl esters by the reaction of the phenyltetrafluorophosphorane with the corresponding trimethylsilylethers derivatives 2a-h, Tab.IV
Reductive aldol-type reaction of α,β-unsaturated esters with aldehydes or ketones in the presence of Rh catalyst and Et2Zn
Sato, Kazuyuki,Isoda, Motoyuki,Tokura, Yoriko,Omura, Keiko,Tarui, Atsushi,Omote, Masaaki,Kumadaki, Itsumaro,Ando, Akira
, p. 5913 - 5915 (2013/10/21)
The reaction of RhCl(PPh3)3 with Et2Zn easily generated a rhodium-hydride complex (Rh-H) that added to α,β-unsaturated esters to form rhodium enolate complexes by formal 1,4-reduction. These rhodium enolates gave the corre
Surface-mediated solid phase reaction. Part 9. A convenient procedure for aldol reaction of ketene silyl acetals with aldehydes on the solid surface of alumina
Ranu, Brindaban C.,Saha, Manika,Bhar, Sanjay
, p. 3065 - 3077 (2007/10/03)
The aldol reaction of ketene silyl acetals with aldehydes proceeds efficiently on the solid surface of alumina impregnated with anhydrous zinc chloride under sonication providing aldol products in high yields and with good stereoselectivity.
Stereoselective reduction of 2-methyl-3-oxo esters (or amides) with sodium borohydride catalyzed by manganese (II) chloride or tetrabutylammonium borohydride. A practical preparation of erythro and threo-3-hydroxy-2-methyl esters (or amides)
Taniguchi, Masahiko,Fujii, Hideaki,Oshima, Koichiro,Utimoto, Kiitiro
, p. 11169 - 11182 (2007/10/02)
erythro-3-Hydroxy-2-methylpropionates or erythro-3-hydroxy-2-methylpropionamides were prepared with high stereoselectivity by NaBH4 reduction of the corresponding 2-methyl-3-oxo esters or 2-methyl-3-oxo amides in the presence of a catalytic amount of manganese(II) chloride. On the other hand, reduction of these substrates with n-Bu4NBH4 provided threo-isomers selectively. erythro-Selective reduction of 2-methyl-3-oxo amides with NaBH3CN in 1N HCl-MeOH is also described.
Design of α-Alkyl β-Hydroxy Esters Suitable for Providing Optical Resolution by Lipase Hydrolysis
Itoh, Toshiyuki,Kuroda, Keiko,Tomosada, Miki,Takagi, Yumiko
, p. 797 - 804 (2007/10/02)
A study of the lipase-catalyzed hydrolyses of various α-substituted β-acetoxy esters revealed that a sulfur functional group in the ester, which could play an important role in the stereorecognition by lipase A6 (Aspergillus sp.) and an anti conformation
Bornanesultam-directed asymmetric synthesis of crystalline, enantiomerically pure syn aldols
Oppolzer, Wolfgang,Blagg, Julian,Rodriguez, Inès,Walther, Eric
, p. 2767 - 2772 (2007/10/02)
N-acylsultams 2 furnish, via aldolization of their enolates 16 with aldehydes, diastereomerically pure, crystalline syn aldols. The absolute configuration of the product is controlled by the choice of the enolate counterion: 16, M = B → 3; 16, M = Li or S
The Use of Cysteine- and Serine-Derived Thiazolidinethiones and Oxazolidinethiones as Efficient Chiral Auxiliaries an Aldol Condensations
Hsiao, Chi-Nung,Liu, Li,Miller, Marvin J.
, p. 2201 - 2206 (2007/10/02)
Cysteine-derived thiazolidinethiones and serine-derived oxazolidinethiones serve as efficient chiral auxiliaries in boron- and tin-mediated aldol condensations.The condensations with a variety of simple aldehydes produced the expected erythro products in high chemical and optical yields.Additional advantages of these chiral auxiliaries were the ease of removal by methanolysis or hydroxaminolysis and their practical recyclability.
Dehydrative Decarboxylation of 2,3-Disubstituted 3-Hydroxycarboxylic Acids with Dimethylformamide Acetals - Mechanistic Studies and Preparative Applicability
Mulzer, Johann,Bruentrup, Gisela
, p. 2057 - 2075 (2007/10/02)
Dimethylformamide dimethylacetal (2a) converts the threo-3-hydroxycarboxylic acids 4 smoothly into the (E)/(Z)-olefins 7/6 only if R2 is an aryl or vinyl substituent.Althougt the reaction exhibits a distinct (E)-selectivity it cannot be considered as a stereo-controlled olefin synthesis.If R2 is alkyl, 2a generates the methyl esters 10 from 4.The erythro-acids 5 react with 2a to give 43 - 95percent of >98percent sterically pure 7.As the key tranformation on the multistep way from 4/5 to 6/7 the fragmentation of the zwitterionic intermediate 11/20 is postulated.
