3290-57-1Relevant articles and documents
Synthesis of 2,4-Dimethylglutaric Acid Monoesters via Enzyme-catalyzed Asymmetric Alcoholysis of meso-2,4-Dimethylglutaric Anhydride
Ozegowski, Ruediger,Kunath, Annamarie,Schick, Hans
, p. 695 - 698 (1993)
1-(2-Methylpropyl) 5-hydrogen (2R,4S)-2,4-dimethylpentanedioate with an enantiomeric excess of 90percent was obtained in a yield of 72percent from meso-2,4-dimethylpentanedioic anhydride and 2-methylpropanol by an asymmetric alcoholysis catalyzed by the l
Preparation of Useful Chiral Lactone Synthons via Stereospecific Enzyme-catalysed Oxidations of meso-Diols
Jakovac, Ignac J.,Ng, George,Lok, Kar P.,Jones, J. Bryan
, p. 515 - 516 (1980)
Horse liver alcohol dehydrogenase-catalysed oxidations of symmetrical acyclic and cyclic meso-diol substrates give chiral γ- and δ-lactones in high yields and of 100percent enantiomeric excess and provide access to a broad range of useful synthons of value in asymmetric syntheses of natural products.
Desymmetrization of acid anhydride with asymmetric esterification catalyzed by chiral phosphoric acid
Yamada, Ken-ichi,Oonishi, Akinori,Kuroda, Yusuke,Harada, Shingo,Kiyama, Hiroki,Yamaoka, Yousuke,Takasu, Kiyosei
supporting information, p. 4098 - 4100 (2016/08/18)
Asymmetric desymmetrization of σ-symmetric acid anhydrides was achieved with chiral phosphoric acid as a Br?nsted acid catalyst. The key of success was finding of benzhydrol and 2,2-diphenylethanol as the nucleophiles of choice. The corresponding half esters were obtained in good yields with high selectivity.
Remote control of regio- and diastereoselectivity in the hydroformylation of bishomoallylic alcohols with catalytic amounts of a reversibly bound directing group
Gruenanger, Christian U.,Breit, Bernhard
supporting information; experimental part, p. 967 - 970 (2010/05/02)
(Figure Presented) Remote and reversible! Phosphinites serve as reversibly bound directing groups for the remote control of the regio- and diastereoselective hydroformylation of bishomoallylic alcohols (see scheme; r.r: regioisomer ratio). The distance between the double bond and the functional hydroxy group to which the directing group is reversibly bound is the longest ever reported.
Intramolecular stereoselective protonation of aldehyde-derived enolates
Kena-diba, Anastasie,Noll, Claudia,Richter, Michael,Gieseler, Marc Timo,Kalesse, Markus
supporting information; experimental part, p. 8367 - 8369 (2010/12/25)
Picking sides: Asymmetric protonation of the titled compounds poses a most significant challenge and has been addressed by taking advantage of internal protonation and subsequent hemiacetal formation to avoid epimerization (see scheme). The substrates employed in these transformations can be easily accessed through a sequence of vinylogous aldol reactions with subsequent conjugate reductions.
Total Synthesis of rapamycin
Ley, Steven V.,Tackett, Miles N.,Maddess, Matthew L.,Anderson, James C.,Brennan, Paul E.,Cappi, Michael W.,Heer, Jag P.,Helgen, Celine,Kori, Masakuni,Kouklovsky, Cyrille,Marsden, Stephen P.,Norman, Joanne,Osborn, David P.,Palomero, Maria A.,Pavey, John B. J.,Pinel, Catherine,Robinson, Lesley A.,Schnaubelt, Juergen,Scott, James S.,Spilling, Christopher D.,Watanabe, Hidenori,Wesson, Kieron E.,Willis, Michael C.
supporting information; experimental part, p. 2874 - 2914 (2009/12/25)
For over 30 years, rapamycin has generated a sustained and intense interest from the scientific community as a result of its exceptional pharmacological properties and challenging structural features. In addition to its well known therapeutic value as a potent immunosuppressive agent, rapamycin and its derivatives have recently gained prominence for the treatment of a wide variety of other human malignancies. Herein we disclose full details of our extensive investigation into the synthesis of rapamycin that culminated in a new and convergent preparation featuring a macro-etherification/catechol-templating strategy for construction of the macrocyclic core of this natural product.
Asymmetric hydrogenation routes to deoxypolyketide chirons
Zhou, Jianguang,Ogle, James W.,Fan, Yubo,Banphavichit, Yorawit,Zhu, Ye,Burgess, Kevin
, p. 7162 - 7170 (2008/03/12)
Asymmetric hydrogenations of monoenes and dienes were performed to obtain terminal deoxypolyketide fragments A and the corresponding internal Chirons B and C. The chiral N-heterocyclic carbene catalyst 1 was used throughout. Modest selectivities for hydrogenations of simple monoenes relayed into high selectivities for preparations of the terminal deoxypolyketide fragments in which either two hydrogenations or one and an optically pure starting material were used. Curiously, the face selectivities for hydrogenation of α,β-unsaturated esters were consistently opposite to those that had been observed for styrene and stilbene derivatives in previous work, and to closely related allylic alcohol and ether derivatives in this work. Plausible mechanisms for this differing behavior were deduced by using DFT calculations. It appears that the origin of the unusual stereoselectivity for the ester derivatives is transient metal-coordination of the ester carbonyl whereas there is no evidence that the allylic alcohol or ethers coordinate. The routes developed to α,ω-functionalized internal deoxypolyketide fragments are extremely practical. These begin with the Roche ester being converted into alkene and, in one case, diene derivatives. Catalyst control prevails in the hydrogenations of these substrates, but there is a significant "substrate vector" (a term we used to describe the influence of the substrate on a catalyst-controlled reaction). This is determined by minimization of 1,3-allylic strain and, in some cases, syn pentane interactions. This substrate vector can be constructively paired with the (dominant) catalyst vector by use of the appropriate enantiomer of 1. In the hydrogenation of a diene derivative, two chiral centers could be formed simultaneously with overall 11:1.0 selectivity; this is the first time this has been achieved in any asymmetric synthesis of a deoxypolyketide fragment. Throughout, diastereo-selectivities of the crude material in the syntheses of α,ω-functionalized internal deoxypolyketide fragments were in excess of 11:1.0 and chromatographically purified samples could be isolated in high yields with dr (dr = diastereomeric ratio) values consistently in excess of 40:1.0.
A Diels-Alder macrocyclization enables an efficient asymmetric synthesis of the antibacterial natural product abyssomicin C
Zapf, Christoph W.,Harrison, Bryce A.,Drahl, Carmen,Sorensen, Erik J.
, p. 6533 - 6537 (2007/10/03)
An efficient and highly diastereoselective intramolecular Diels-Alder reaction is the basis of a concise asymmetric synthesis of the potent antibacterial natural product abyssomicin C (see formula). The complexity of the target structure was reduced to three fragments and required two carbonyl addition reactions to achieve key bond formations. (Figure Presented).
Highly enantioselective catalytic thiolysis of prochiral cyclic dicarboxylic anhydrides utilizing a bifunctional chiral sulfonamide
Honjo, Takashi,Sano, Shigeki,Shiro, Motoo,Nagao, Yoshimitsu
, p. 5838 - 5841 (2007/10/03)
(Chemical Equation Presented) A catalytic desymmetrization is achieved for various prochiral dicarboxylic anhydrides with yields of 87-100% and ee values of 83-98% through the title reaction (see scheme; Bn = benzyl). The bifunctional effect of the chiral sulfonamide catalyst was clarified on the basis of unsuccessful asymmetric induction by using the related chiral sulfonamides.
All-catalytic, efficient, and asymmetric synthesis of α,ω- diheterofunctional reduced polypropionates via "one-pot" Zr-catalyzed asymmetric carboalumination - Pd-catalyzed cross-coupling tandem process
Novak, Tibor,Tan, Ze,Liang, Bo,Negishi, Ei-Ichi
, p. 2838 - 2839 (2007/10/03)
A highly efficient method for the synthesis of stereochemically pure (≥99% ee and >50/1 dr) α,ω-diheterofunctional reduced polypropionates has been developed. The essential features of the method are represented by the conversion of inexpensive styrene in
