141993-16-0Relevant articles and documents
MANGANESE(III)-PROMOTED OXIDATIVE FREE-RADICAL CYCLIZATIONS OF β-KETO IMIDES: ASYMMETRIC INDUCTION WITH OPPOLZER'S CHIRAL SULTAM
Zoretic, Phillip A.,Weng, Xiaoyu,Biggers, Christopher K.,Biggers, Michael S.,Caspar, Myron L.,Davis, Donald G.
, p. 2637 - 2640 (1992)
Oxidative free-radical cyclization of the unsaturated β-keto imide 3 containing Oppolzer's D-camphor sultam as a chiral auxiliary was studied.Intramolecularly promoted oxidative free-radical cyclization of 3 with Mn(III) in the presence of Cu(II) produced the stereoisomeric cis-hydrindanones 4 and 5 in a 3:1 ratio at 25 deg C.
Palladium-Catalyzed Stereoselective Cyclization of in Situ Formed Allenyl Hemiacetals: Synthesis of Rosuvastatin and Pitavastatin
Spreider, Pierre A.,Breit, Bernhard
supporting information, p. 3286 - 3290 (2018/06/11)
A diastereoselective palladium-catalyzed cyclization of allenyl hemiacetals is described. It permits the selective synthesis of 1,3-dioxane derivatives, precursors for syn-configured 1,3-diols which make an appearance in all of the statin representatives. The reaction allows the total synthesis of Rosuvastatin and Pitavastatin in a straightforward fashion.
Diastereoselective allylation of N-glyoxyloyl-(2R)-bornane-10,2-sultam and (1R)-8-phenylmenthyl glyoxylate: Synthesis of (2S,4S)-2-hydroxy-4-hydroxymethyl- 4-butanolide
Kiegiel, Katarzyna,Balakier, Tomasz,Kwiatkowski, Piotr,Jurczak, Janusz
, p. 3869 - 3878 (2007/10/03)
The diastereoselective addition of allylsilanes and allylstannanes to N-glyoxyloyl-(2R)-bornane-10,2-sultam 1 and (1R)-8-phenylmenthyl glyoxylate 7 in the presence of Lewis acids has been studied. We obtained diastereoselectivities up to 84% and 94% for the allylation of 2 and 7, respectively. The application of the allylation products of 1 or 2 in the synthesis of 4-butanolides, for example (2S,4S)-2-hydroxy-4-hydroxymethyl-4- butanolide 13 is presented.
The total synthesis and biological assessment of trans-epothilone A
Altmann, Karl-Heinz,Bold, Guido,Caravatti, Giorgio,Denni, Donatienne,Floersheimer, Andreas,Schmidt, Alfred,Rihs, Grety,Wartmann, Markus
, p. 4086 - 4110 (2007/10/03)
The total synthesis of (12S,13S)-trans-epothilone A (1a) was achieved based on two different convergent strategies. In a first-generation approach, construction of the C(11)-C(12) bond by Pd0-catalyzed Negishi-type coupling between the C(12)-to-C(15) trans-vinyl iodide 5 and the C(7)-to-C(11) alkyl iodide 4 preceded the (nonselective) formation of the C(6)-C(7) bond by aldol reaction between the C(7)-to-C(15) aldehyde 25 and the dianion derived from the C(1)-to-C(6) acid 3. The lack of selectivity in the aldol step was addressed in a second-generation approach, which involved construction of the C(6)-C(7) bond in a highly diastereoselective fashion through reaction between the acetonide-protected C(l)-to-C(6) diol 31 ('Schinzer's ketone') and the C(7)-to-C(11) aldehyde 30. As part of this strategy, the C(11)-C(12) bond was established subsequent to the critical aldol step and was based on B-alkyl Suzuki coupling between the C(1)-to-C(11) fragment 40 and C(12)-to-C(15) trans-vinyl iodide 5. Both approaches converged at the stage of the 3-O, 7-O-bis-TBS-protected seco acid 27, which was converted to trans-deoxyepothilone A (2) via Yamaguchi macrolactonization and subsequent deprotection. Stereoselective epoxidation of the trans C(12)-C(13) bond could be achieved by epoxidation with Oxone in the presence of the catalyst 1,2:4,5-di-O-isopropylidene-L-erythro-2,3-hexodiuro-2,6-pyranose (42a), which provided a 8:1 mixture of 1a and its (12R,13R)-epoxide isomer 1b in 27% yield (54% based on recovered starting material). The absolute configuration of 1a was established by X-ray crystallography. Compound 1a is at least equipotent with natural epothilone A in its ability to induce tubulin polymerization and to inhibit the growth of human cancer cell lines in vitro. In contrast, the biological activity of 1b is at least two orders of magnitude lower than that of epothilone A or 1a.