2749-86-2Relevant articles and documents
Part 2: Efficient strategies for the construction of variably substituted bicyclo[5.3.1]undecenones (AB-taxane ring systems) and their conversion to tricyclo[9.3.1.03,8]pentadecenones (ABC taxane ring systems) and bicyclo[2.2.2]octanones
Villalva-Servin, Nidia P.,Laurent, Alain,Fallis, Alex G.
, p. 227 - 239 (2004)
The extension of our strategies for the construction of cyclic molecules containing variably substituted bicyclo[5.3.1]undecenones (AB taxane ring systems) for the synthesis of the tricyclo[9.3.1.03,8]pentadecenone (ABC taxane ring system) and bicyclo[2.2.2]octanones are described. These routes employ a multi-component coupling protocol that employs sequential magnesium-mediated carbometallation of allyl-substituted propargyl alcohols followed by diastereoselective Lewis acid catalyzed intramolecular Diels-Alder reactions (TMDA). Subsequent ring-closing metathesis (RCM) afforded the ABC taxane core structure. Enone accelerated [3,3] sigmatropic rearrangements (Cope rearrangements) generated the bicyclo[2.2.2]octanone nucleus. In the presence of a Lewis acid, the dienophile precursor underwent a tandem reaction via the adduct directly to the bicyclo[2.2.2]octanones. This is the first example of a novel enone accelerated carbocycle Cope rearrangement and provides direct access to bicyclo[2.2.2]octanones by a new route that compliments the traditional cyclohexadiene cycloaddition approach.
Copper-catalyzed enantioselective alkene carboetherification for the synthesis of saturated six-membered cyclic ethers
Berhane, Ilyas A.,Burde, Ameya S.,Chemler, Sherry R.,Kennedy-Ellis, Jonathan J.,Zurek, Eva
supporting information, p. 10099 - 10102 (2021/10/06)
The enantioselective copper-catalyzed oxidative coupling of alkenols with styrenes for the construction of dihydropyrans, isochromans, pyrans and morpholines is reported. A concise formal synthesis of a σ1receptor ligand using this alkene carbo
Stereoselective Synthesis of C1–C7 and C6–C22 Fragments of Phostriecin, Goniothalamines, and Their Analogues
Purushotham Reddy,Vasudeva Reddy,Sabitha, Gowravaram
, p. 4389 - 4399 (2018/09/11)
The stereoselective synthesis of two fragments (C1–C7 and C6–C22) of the anti-tumor agent phostriecin has been achieved. The chiral hydroxy-vinyl-δ-lactone building block (fragment C1–C7) was subsequently utilized for the synthesis of 5-hydroxygoniothalamin, 5-acetoxygoniothalamin, and their derivatives.
Lactone radical cyclizations and cyclization cascades mediated by SmI 2-H2O
Parmar, Dixit,Matsubara, Hiroshi,Price, Kieran,Spain, Malcolm,Procter, David J.
supporting information; experimental part, p. 12751 - 12757 (2012/09/05)
Unsaturated lactones undergo reductive radical cyclizations upon treatment with SmI2-H2O to give decorated cycloheptanes in a single highly selective operation during which up to three contiguous stereocenters are generated. Furthermore, cascade processes involving lactones bearing two alkenes, an alkene and an alkyne, or an allene and an alkene allow "one-pot" access to biologically significant molecular scaffolds with the construction of up to four contiguous stereocenters. The cyclizations proceed by the trapping of radical anions formed by electron transfer reduction of the lactone carbonyl.
Multidirectional cobalt-catalyzed diels-alder/1,4-hydrovinylation sequences
Erver, Florian,Kuttner, Julian R.,Hilt, Gerhard
, p. 8375 - 8385 (2012/11/07)
The combination of two powerful cobalt-catalyzed carbon-carbon bond forming transformations, namely, the Diels-Alder and the 1,4-hydrovinylation reaction, in a tandem or a sequential one-pot procedure, opened up a concise and efficient route to polysubstituted aromatic systems and cyclohex-3-enone derivatives. Furthermore, ozonolysis of the latter products led to polycarbonyl compounds with tailored carbonyl group distances which could be characterized via their respective BF2-borinane complexes. The cobalt catalysts tolerated several functional groups, and a flexible approach to polyfunctionalized compounds in concise fashion was described.
Stereoselective synthesis of (-)-α-conhydrine
Reddipalli, Gowrisankar,Venkataiah, Mallam,Fadnavis, Nitin W.
experimental part, p. 1778 - 1783 (2012/01/04)
(-)-α-Conhydrine was synthesized from propargyl alcohol in 20% overall yield in nine steps. The key intermediates were obtained via a regioselective epoxide opening, cross-metathesis, tandem hydrogenation and hydrogenolysis, and stereoselective dihydroxyl
Total synthesis and absolute configuration of macrocidin A, a cyclophane tetramic acid natural product
Yoshinari, Tomohiro,Ohmori, Ken,Schrems, Marcus G.,Pfaltz, Andreas,Suzuki, Keisuke
supporting information; experimental part, p. 881 - 885 (2010/05/02)
(Figure Presented) Stereocontrolled access to the cyclophane framework of macrocidin A has been achieved for the first time. The key steps include the iridium-catalyzed asymmetric hydrogenation without fission of the C-I bond, the macrolactam formation by intramolecular ketene trapping, and the Lacey-Dieckmann cyclization for the construction of the tetramic acid ring.
Copper catalyzed regioselective coupling of allylic halides and alkynes promoted by weak inorganic bases
Bieber, Lothar W.,da Silva, Margarete F.
, p. 7088 - 7090 (2008/03/11)
Allylic halides and terminal alkynes couple under CuI catalysis in DMSO or DMF solution. In most cases, sodium carbonate or bicarbonate is sufficient to promote the reaction; less reactive alkynes require catalytic amounts of DBU. Bifunctional alkynes and halides can be reacted selectively according to the stoichiometry used. Trimethylsilyl, hydroxyl, ester and halide groups are tolerated in the alkyne. Most halides react without allylic rearrangement. The method is suitable for the synthesis of functionalized enynes.
A concise stereoselective total synthesis of (2R,2′R)-threo-(+)- methyl-phenidate via a ring-closing metathesis protocol
Krishna, Palakodety Radha,Lopinti, Krishnarao
, p. 1742 - 1744 (2007/12/31)
In the synthesis of (2R,2′R)-threo-(+)-methylphenidate, a ring-closing metathesis approach was adopted to construct the piperidine ring, while Sharpless asymmetric epoxidation was used for the efficient generation of two contiguous stereocenters. Georg Th
Allylacetylenes and their derivatives as inhibitors of steel corrosion in sulfuric acid
Veliev,Agaev,Shatirova,Chalabieva,Geidarova,Alieva
, p. 1829 - 1834 (2008/02/08)
New functionalized derivatives of allylacetylenes were prepared, and their ability to inhibit corrosion of St.3 low-carbon steel in 5 N sulfuric acid was studied. The effectiveness of inhibition of steel corrosion was studied in relation to the structure of acetylene derivatives, their concentration, and temperature of acidic medium.
