6305-59-5Relevant academic research and scientific papers
Manganese-promoted regioselective ring-opening of 2,3-epoxy acid derivatives: a new route to α-hydroxy acid derivatives
Concellon, Jose M.,Bernad, Pablo L.,Rodriguez-Solla, Humberto,Diaz, Pamela
experimental part, p. 2178 - 2184 (2009/12/31)
A simple and general methodology directed towards the synthesis 3-aryl-2-hydroxy amides, or esters with total regioselectivity from the easily available 2,3-epoxy amides or esters, promoted by active manganese is described. Utilizing enantiopure epoxy amides as starting materials, the corresponding 3-aryl-2-hydroxy amides in enantiopure form are also available. Some synthetic applications of selected examples of 3-aryl-2-hydroxy carboxylic acid derivatives are shown. A mechanism has been proposed to explain this novel reaction.
An efficient cobalt(I)-catalysed reformatsky reaction using α-chloro esters
Lombardo, Marco,Gualandi, Alessandra,Pasi, Filippo,Trombini, Claudio
, p. 465 - 468 (2008/02/08)
An efficient cobalt(I)-catalysed Reformatsky reaction using α-chloro esters has been developed. The catalyst is prepared by reducing the cobalt(II) chloride (5%)/1,2-bis(diphenylphosphino)ethane (dppe)(5%)/zinc iodide (10%) system with zinc metal in acetonitrile in the presence of both the α-chloro ester and the carbonyl compound; good to excellent conversions to β-hydroxy esters are obtained at room temperature in 2.5 h.
BCl3- and TiCl4-mediated reductions of β-hydroxy ketones
Sarko, Christopher R.,Collibee, Scott E.,Knorr, Allison L.,DiMare, Marcello
, p. 868 - 873 (2007/10/03)
Syn-selective reduction protocols for β-hydroxy ketones are described exploiting the intermediacy of titanium and boron chelates derived from TiCl4 and BCl3, respectively. Reductions are conducted at -78°C in CH2Cl2/
Low-valent Tantalum-mediated Reaction
Aoyagi, Yutaka,Tanaka, Wataru,Ohta, Akihiro
, p. 1225 - 1226 (2007/10/02)
Treatment of a mixture of α-halogeno-esters and carbonyl compounds with low valent tantalum prepared readily from tantalum(V) chloride and activated zinc, afforded β-hydroxy esters in moderate to good yields.
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.
A PRACTICAL AND STEREOSELECTIVE REDUCTION OF 3-KETO-2-METHYL ESTERS OR 3-KETO-2-METHYL AMIDES INTO ERYTHRO-3-HYDROXY-2-METHYL ESTERS OR ERYTHRO-3-HYDROXY-2-METHYL AMIDES WITH NaBH4 CATALYZED BY MnCl2
Fujii, Hideaki,Oshima, Koichiro,Utimoto, Kiitiro
, p. 6147 - 6150 (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 3-keto esters or 3-keto amides in the presence of a catalytic amount of MnCl2.
SmI2-INDUCED HIGHLY REGIOSELECTIVE REDUCTION OF α,β-EPOXY ESTERS AND γ,δ-EPOXY-α,β-UNSATURATED ESTERS. AN EFFICIENT ROUTE TO OPTICALLY ACTIVE β-HYDROXY AND δ-HYDROXY ESTERS
Otsubo, Kenji,Inanaga, Junji,Yamaguchi, Masaru
, p. 4437 - 4440 (2007/10/02)
α,β-Epoxy esters were rapidly reduced at room temperature to yield β-hydroxy esters with retention of the configurations at the β-carbon atoms by using SmI2-THF-HMPA system in the presence of N,N-dimethylaminoethanol (DMAE).The conditions were successfully applied to the synthesis of vinylogous δ-hydroxy esters.
