177987-29-0Relevant academic research and scientific papers
Ru-catalyzed asymmetric transfer hydrogenation of α-acyl butyrolactone via dynamic kinetic resolution: Asymmetric synthesis of bis-THF alcohol intermediate of darunavir
More, Ganesh V.,Malekar, Pushpa V.,Kalshetti, Rupali G.,Shinde, Mahesh H.,Ramana, Chepuri V.
supporting information, (2021/02/16)
The Ru-catalyzed enantio- and diastereoselective dynamic kinetic resolution of α-(benzyloxy/benzoyloxy)acyl-γ-butyrolactones has been examined via transfer hydrogenation. Employing the in situ prepared (R,R)-Ru-FsDPEN catalyst, the transfer hydrogenation of using formic acid/triethylamine at rt gave the corresponding (S)-3-((S)-2-(benzyloxy/benzoyloxy)-1-hydroxyethyl)dihydrofuran-2(3H)-one with good to excellent diastereo- and enantioselectivity. One of the resulting hydrogenation product prepared on gram scales was utilized for the synthesis of (3R,3aS,6aR)-hexahydrofuro[2,3–b]furan-3-ol (1), a key synthetic intermediate of various HIV protease inhibitors such as darunavir with excellent enantio- (95% ee) and diastereoselectivities (dr 95:5).
Enzymatic process for the preparation of butyrolactones
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, (2013/09/12)
The invention relates to a process for the preparation of a compound of formula wherein R1 is selected from the group consisting of hydrogen, C2-11-acyl, C4-9-cycloalkanoyl, aryl, aralkyl, aroyl, hetaryl, hetaralkyl and hetaroyl, comprising a biotransformation of a compound of formula wherein R1 is as defined above, wherein said biotransformation is carried out using a polypeptide having aldo-keto reductase activity or a microorganism containing same.
Highly diastereo- and enantioselective catalytic synthesis of the bis-tetrahydrofuran alcohol of Brecanavir and Darunavir
Black, David M.,Davis, Roman,Doan, Brian D.,Lovelace, Tom C.,Millar, Alan,Toczko, Jennifer F.,Xie, Shiping
, p. 2015 - 2019 (2008/12/22)
An efficient highly diastereo- and enantioselective synthesis of the bis-tetrahydrofuran (bis-THF) alcohol of several HIV protease inhibitors, including Brecanavir and Darunavir, has been achieved utilizing an Evans Mukaiyama aldol reaction of (benzyloxy)acetaldehyde and a silyl ketene acetal. The lactone alcohol intermediate from the catalytic aldol reaction was reduced to a lactol. Palladium catalyzed hydrogenolysis removed the benzyl protection and promoted an in situ cyclization to form the epimer of the bis-THF alcohol in a 98:2 diastereomeric ratio and 97:3 enantiomeric ratio. The alcohol epimer was readily converted to the target in two steps by oxidation to a ketone followed by highly selective reduction to the bis-THF alcohol.
Production method of hexahydrofurofuranol derivative, intermediate therefor and production method thereof
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, (2008/06/13)
The present invention provides a method for producing compound (XIV) useful as an intermediate for pharmaceutical agents efficiently and economically on an industrial scale without using ozone oxidation and highly toxic reagent, and an intermediate used for this method. Particularly, the present invention provides a method for producing a compound having an absolute configuration represented by the formula (XV) and an enantiomer thereof without using a technique such as optical resolution and the like, and an intermediate used for this method. (1) Compound (XIII) as a starting material is led to compound (I), and after introducing a protecting group, subjected to reduction and cyclization to give compound (XIV). Particularly, compound (XIII) as a material is led to compound (I) via compound (XX) to produce compound (XIV). Using an optically active compound (XIII) as a starting material, a compound having an absolute configuration represented by the formula (XV) and the like are produced highly stereoselectively. (2) Compound (XXI) as a starting material is stereoselectively reduced to give compound (XXII), and by introduction of a protecting group, reduction and cyclization, compound (XXVI) is obtained, and by inverting hydroxyl group, compound (XV) is produced. wherein each symbol is as defined in the specification.
Production method of hexahydrofurofuranol derivative, intermediate therefor and production method thereof
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Page/Page column 31, (2008/06/13)
The present invention provides a method for producing compound (XIV) useful as an intermediate for pharmaceutical agents efficiently and economically on an industrial scale without using ozone oxidation and highly toxic reagent, and an intermediate used for this method. Particularly, the present invention provides a method for producing a compound having an absolute configuration represented by the formula (XV) and an enantiomer thereof without using a technique such as optical resolution and the like, and an intermediate used for this method. (1) Compound (XIII) as a starting material is led to compound (I), and after introducing a protecting group, subjected to reduction and cyclization to give compound (XIV). Particularly, compound (XIII) as a material is led to compound (I) via compound (XX) to produce compound (XIV). Using an optically active compound (XIII) as a starting material, a compound having an absolute configuration represented by the formula (XV) and the like are produced highly stereoselectively. (2) Compound (XXI) as a starting material is stereoselectively reduced to give compound (XXII), and by introduction of a protecting group, reduction and cyclization, compound (XXVI) is obtained, and by inverting hydroxyl group, compound (XV) is produced. wherein each symbol is as defined in the specification.
C2-symmetric copper(II) complexes as Chiral Lewis acids. Scope and mechanism of catalytic enantioselective aldol additions of enolsilanes to (benzyloxy)acetaldehyde
Evans, David A.,Kozlowski, Marisa C.,Murry, Jerry A.,Burgey, Christopher S.,Campos, Kevin R.,Connell, Brian T.,Staples, Richard J.
, p. 669 - 685 (2007/10/03)
C2-Symmetric bis(oxazolinyl)pyridine (pybox)-Cu(II) complexes have been shown to catalyze enantioselective Mukaiyama aldol reactions between (benzyloxy)acetaldehyde and a variety of silylketene acetals. The aldol products are generated in high yields and in 92-99% enantiomeric excess using as little as 0.5 mol % of chiral catalyst [Cu((S,S)-Ph-pybox)](SbP6)2. With substituted silylketene acetals, syn reaction diastereo-selection ranging from 95:5 to 97:3 and enantioselectivities ≥95% are observed. Investigation into the reaction mechanism utilizing doubly labeled silylketene acetals indicates that the silyl-transfer step is intermolecular. Further mechanistic studies revealed a significant positive nonlinear effect, proposed to arise from the selective formation of the [Cu((S,S)-Ph-pybox)((R,R)-Ph-pybox)](SbF6)2 2:1 ligand:metal complex. A stereochemical model is presented in which chelation of (benzyloxy)acetaldehyde to the metal center to form a square pyramidal copper intermediate accounts for the observed sense of induction. Support for this proposal has been obtained from double stereodifferentiating reactions, EPR spectroscopy, ESI spectrometry, and, ultimately, the X-ray crystal structure of the aldehyde bound to the catalyst. The C2-symmetric bis(oxazolinyl)-Cu(II) complex [Cu((S,S)-tert-Bu-box)](OTf)2 is also an efficient catalyst for the aldol reaction, but the scope with this system is not as broad.
