6317-49-3Relevant articles and documents
CuCN catalyzed one pot synthesis of γ-keto diesters: Domino double Michael addition followed by Nef reaction
Farooq, Saleem,Sangwan, Payare L.,Aleti, Rajeshwar R.,Chinthakindi, Praveen K.,Qurishi, Mushtaq A.,Koul, Surrinder
supporting information; experimental part, p. 3305 - 3309 (2012/08/07)
An efficient one pot synthesis of γ-keto diesters through double Michael addition coupled with Nef reaction in the presence of CuCN catalyst and Cs2CO3 base is described. The reaction proceeds rapidly in DCM to give the products in good yields. A plausible mechanism is proposed.
Unsymmetrical Ketone Synthesis via a Three-Component Connection Reaction of Organozincs, Allylating Agents, and Carbon Monoxide
Yasui, Kengo,Fugami, Keigo,Tanaka, Shuji,Tamaru, Yoshinao
, p. 1365 - 1380 (2007/10/02)
A wide variety of organozincs (diethylzinc, alkylzinc halides, and organozincs 2, 5, and 9a-e, functionalized with ester and nitrile groups) undergo a three-component connection reaction with carbon monoxide and allylic benzoates or phosphates 1a-h to furnish unsymmetrical ketones, e.g., 3, 6, and 10, in good yields uder 1 atm of carbon monoxide at ambient temperature by the catalysis of tetrakis(triphenylphosphine)palladium in THF/HMPA.The regio- and stereoselectivities of the present carbonylation show marked contrast to those reported for the palladium-catalyzed carbonylation of usymmetrical allylic substrates.For example, the reaction of crotyl benzoate with octylzinc iodide provides all the possible stereo- and regioisomers, i.e., cis- and trans-2-butenyl and 1-methyl-2-propenyl octyl ketones in comparable amounts.The carbonylative coupling of carvyl phosphates, trans- and cis-1h, and γ-zincio ester 5 is stereospecific and proceeds with inversion of configuration at the allylic stereocenters to furnish cis- and trans-6h, respectively, as single diastereomers.In the absence of HMPA, the reaction feature changes dramatically and lactones 12 and 13 (composed of organozincs, carbon monoxide, and allylating agents in the ratios of 1:1:2 and 2:1:1, respectively) and symmetrical keto diesters 14 (composed of 2 mol of organozincs and 1 mol of carbon monoxide) are formed in varying ratios depending on the reaction conditions.Synthetic scope of the unsymmetrical ketones and mechanistic rationale for these unique and unprecedented reaction behaviors are discussed.
Lipase-Catalyzed Preparation of Optically Active γ-Butyrolactones in Organic Solvents
Gutman, Arie L.,Zuobi, Kheir,Bravdo, Tamar
, p. 3546 - 3552 (2007/10/02)
Lipases in anhydrous organic solvents catalyze the lactonization of esters of γ-hydroxy carboxylic acids with a high degree of stereospecifity.Under these conditions the lipases exhibit both enantioselectivity and prochiral selectivity.We exploited the enzymes' enantioselectivity for synthesis of chiral lactones from racemic γ-hydroxy esters and their prochiral stereospecifity, i.e. the ability to discriminate between enantiotopic groups of a prochiral molecule, for the enantioconvergent lactonization of symmetrical γ-hydroxy diesters.This approach was used to develop a convenient, high yielding, and stereoselective route to several optically active γ-substituted γ-butyrolactones.
