594847-89-9Relevant articles and documents
Chemoselectivity Control in the Asymmetric Hydrogenation of γ- and δ-Keto Esters into Hydroxy Esters or Diols
Arai, Noriyoshi,Namba, Takanori,Kawaguchi, Kei,Matsumoto, Yuki,Ohkuma, Takeshi
supporting information, p. 1386 - 1389 (2018/01/01)
The asymmetric hydrogenation of aromatic γ- and δ-keto esters into optically active hydroxy esters or diols under the catalysis of a novel DIPSkewphos/3-AMIQ–RuII complex was studied. Under the optimized conditions (8 atm H2, Ru complex/t-C4H9OK=1:3.5, 25 °C) the γ- and δ-hydroxy esters (including γ-lactones) were obtained quantitatively with 97–99 % ee. When the reaction was conducted under somewhat harsh conditions (20 atm H2, [t-C4H9OK]=50 mm, 40 °C), the 1,4- and 1,5-diols were obtained predominantly with 95–99 % ee. The reactivity of the ester group was notably dependent on the length of the carbon spacer between the two carbonyl moieties of the substrate. The reaction of β- and ?-keto esters selectively afforded the hydroxy esters regardless of the reaction conditions. This catalyst system was applied to the enantioselective and regioselective (for one of the two ester groups) hydrogenation of a γ-?-diketo diester into a trihydroxy ester.
One-pot asymmetric synthesis of 2-and 2,3-disubstituted tetrahydrofuran derivatives
Ramachandran, P. Veeraraghavan,Nair, Hari N. G.,Gagare, Pravin D.
, p. 5394 - 5398 (2012/08/07)
A novel and convenient one-pot asymmetric synthesis of 2- and 2,3-disubstituted tetrahydrofurans has been achieved in 56-81% yields and 86-99% ee from aliphatic and aromatic aldehydes via an allyl/crotyl/ alkoxyallylboration-hydroboration-iodination-cyclization reaction sequence.
Application of a one-pot lipase resolution strategy for the synthesis of chiral γ- and δ-lactones
Kamal, Ahmed,Sandbhor, Mahendra,Shaik, Ahmad Ali
, p. 1575 - 1580 (2007/10/03)
A successful one-pot reduction of γ-ketoesters, δ-ketoesters and lactones to the corresponding 1,4- and 1,5-diols followed by a lipase catalyzed kinetic resolution coupled with hydrolysis to afford optically active diols is described. The synthetic utility of this one-pot method was illustrated by the oxidation of these chiral diols to respective chiral γ-butyrolactone and δ-lactones. Lipase from Pseudomonas cepacia, immobilized on ceramic afforded the product with high enantiomeric excess in good yields under mild reaction conditions. This approach has been used to develop a convenient enantioselective route for several γ- and δ-lactones using achiral and corresponding racemic starting material.