136826-75-0Relevant academic research and scientific papers
Stereospecific preparation of glycidic esters from 2-chloro-3-hydroxyesters. Application to the synthesis of (2R,3R)-3-phenylisoserine
Cabon,Buisson,Larcheveque,Azerad
, p. 2211 - 2218 (1995)
Cis- and trans-glycidic esters may be synthesized in high enantiomeric purities by cyclisation with potassium carbonate in DMF of the corresponding syn- or anti-2-chloro-3-hydroxyesters, prepared by microbial reduction of 2-chloro-3-oxoesters. In contrast, more basic media such as sodium ethylate afford exclusively the trans-isomer, whatever the stereochemistry of the starting 2-chloro-3-hydroxyester is. Cyclisation of deuterated compounds showed that this result was due to a rapid isomerisation of the syn esters into anti isomers before cyclisation. An application of this reaction to the synthesis of (2R,3R)-3-phenylisoserine is described.
Organic reactions catalyzed by methylrhenium trioxide: Reactions of ethyl diazoacetate and organic azides
Zhu, Zuolin,Espenson, James H.
, p. 9901 - 9907 (2007/10/03)
Methylrhenium trioxide (CH3ReO3 or MTO) catalyzes several classes of reactions of ethyl diazoacetate, EDA. It is the first high valent oxo complex for carbene transfer. Under mild conditions and in the absence of other substrates, EDA was converted to a 9:1 mixture of diethyl maleate and diethyl fumarate. In the presence of alcohols, α-alkoxy ethyl acetates were obtained in good yield. The yields dropped for the larger and more branched alcohols, the balance of material being diethyl maleate and fumarate. An electron-donating group in the para position of phenols favors the formation of α-phenoxy ethyl acetates. The use of EDA to form α-thio ethyl acetates and N-substituted glycine ethyl esters, on the other hand, is hardly affected by the size or structure of the parent thiol or amine, with all of these reactions proceeding in high yield. MTO-catalyzed cycloaddition reactions occur between EDA and aromatic imines, olefins, and carbonyl compounds. Three-membered ring products are formed: aziridines, cyclopropanes, and epoxides, respectively. The reactions favor the formation of trans products, and provide a convenient route for the preparation of aziridines. Intermediate carbenoid and nitrenoid species have been proposed. In the presence of an oxygen source such as an epoxide, ethyl diazoacetate and azibenzil are converted to an oxalic acid monoethyl ester and tobenzil; at the same time the epoxide was converted to an olefin. These results provide further support for the proposed intermediate, a cyclic species containing Re, O, and CHCO2Et (or, occasionally, CPhC(O)Ph)in a three-membered ring.
A convenient synthesis of aziridine-2-carboxylic esters
Legters, Johan,Thijs, Lambertus,Zwanenburg, Binne
, p. 1 - 15 (2007/10/02)
Optically active oxirane-2-carboxylic esters, prepared from allylic alcohols employing the Sharpless epoxidation, were treated with sodium azide.The azido alcohols obtained were subsequently converted into aziridine-2-carboxylic esters by reaction with triphenylphosphine, in good yields and with high optical purity.Various racemic oxirane-2-carboxylic esters were subjected to the same sequence of reactions.
Synthesis and Reactions of 3-Hydroxy-2-nosyloxy Esters Produced by the Stereoselective Reduction of 2-Nosyloxy-3-keto Esters
Hoffman, Robert V.,Kim, Hwa-Ok
, p. 6759 - 6764 (2007/10/02)
The reduction of 2-nosyloxy-3-keto esters is an effective method for the preparation of 3-hydroxy-2-nosyloxy esters.The reduction is stereoselective for the syn isomer.The anti isomer can be produced as the major product by the addition of p-nitrobenzenesulfonyl peroxide to ketene bis-silyl acetal derivatives of 3-hydroxy esters.The diastereomers are separable chromatographically and can be converted stereospecifically to glycidic esters and 2-azido-3-hydroxy esters.As such they appear to have excellent potential as versatile synthetic intermediates for the synthesis of 1,2,3-trifunctional substances.
