- Diastereoselective Addition of Prochiral Nucleophilic Alkenes to α-Chiral N-Sulfonyl Imines
-
The Lewis-acid-promoted addition of prochiral E- and Z-allyl nucleophiles to chiral α-alkoxy N-tosyl imines is described. Alkene geometry is selectively transferred to the newly formed carbon-carbon bond, resulting in stereochemical control of C1, C2, and C3 of the resulting 2-alkoxy-3-N-tosyl-4-alkyl-5-hexene products. A computational analysis to elucidate the high selectivity is also presented. This methodology was employed in the synthesis of two naturally occurring isomers of clausenamide.
- Ando, Kaori,Fettinger, James,Gutierrez, David A.,Houk, K. N.,Shaw, Jared T.
-
supporting information
p. 1164 - 1168
(2022/02/14)
-
- COMPOUNDS AND METHODS FOR TARGETED DEGRADATION OF KRAS
-
Bifunctional compounds, which find utility as modulators of Kirsten ras sarcoma protein (KRas or KRAS), are described herein. In particular, the hetero-bifunctional compounds of the present disclosure contain on one end a moiety that binds to the Von Hippel-Lindau E3 ubiquitin ligase and on the other end a moiety which binds KRas, such that the target protein is placed in proximity to the ubiquitin ligase to effect degradation (and inhibition) of target protein. The heterobifunctional compounds of the present disclosure exhibit a broad range of pharmacological activities associated with degradation/inhibition of target protein. Diseases or disorders that result from aberrant regulation of the target protein are treated or prevented with compounds and compositions of the present disclosure.
- -
-
Paragraph 00235
(2021/10/15)
-
- A Concise Synthesis of the Key Tetrahydrofuran Moieties of Caruifolin A and EBC-342
-
A common strategy for the concise synthesis of the key tetrahydrofuran moieties of caruifolin A and EBC-342 is presented. Asymmetric dihydroxylation and intramolecular SN2-cyclization are key strategic reactions for the synthesis of the furan f
- Fernandes, Rodney A.,Bethi, Venkati
-
p. 6922 - 6928
(2020/06/10)
-
- MODULATORS OF PROTEOLYSIS AND ASSOCIATED METHODS OF USE
-
The present disclosure relates to bifunctional compounds, which find utility as modulators of Kirsten rat sarcoma protein (target protein). In particular, the present disclosure is directed to bifunctional compounds, which contain on one end a Von Hippel-Lindau, cereblon, Inhibitors of Apotosis Proteins or mouse double-minute homolog 2 ligand which binds to the respective E3 ubiquitin ligase and on the other end a moiety which binds the target protein, such that the target protein is placed in proximity to the ubiquitin ligase to effect degradation (and inhibition) of target protein. The present disclosure exhibits a broad range of pharmacological activities associated with degradation/inhibition of target protein. Diseases or disorders that result from aggregation, accumulation, and/or overactivation of the target protein are treated or prevented with compounds and compositions of the present disclosure.
- -
-
Paragraph 00763-00764
(2019/10/29)
-
- Synergistic substrate and catalyst effects in the addition of trimethylsilyl cyanide to imines derived from lactic acid
-
Trimethylsilylcyanide was added to various imines derived from (2S)-ethyl lactate in the presence of Lewis acids to provide both syn- and anti- β-hydroxy-α-aminonitrile stereoisomers. Syn-products were found to be the major in most instances, however, ant
- Fields, Alexander M.,Jones, Simon
-
p. 3413 - 3420
(2019/05/16)
-
- A Unified Synthetic Approach to Optically Pure Curvularin-Type Metabolites
-
A unified and concise approach to the synthesis of nine curvularin-type metabolites and two analogues has been developed with few steps and high yields. Among them, sumalactones A-D were synthesized for the first time. The key steps in this approach inclu
- Allu, Srinivasa Rao,Banne, Sreenivas,Jiang, Jia,Qi, Na,Guo, Jian,He, Yun
-
p. 7227 - 7237
(2019/06/07)
-
- A Br?nsted Acid Catalyzed Cascade Reaction for the Conversion of Indoles to α-(3-Indolyl) Ketones by Using 2-Benzyloxy Aldehydes
-
A Br?nsted acid catalyzed, operationally simple, scalable route to several functionalized α-(3-indolyl) ketones has been developed and the long-standing regioisomeric issue has been eliminated by choosing appropriate carbonyls. A readily available and cheap bottle reagent was used as the catalyst. This protocol was also applicable to the synthesis of densely functionalized α-(3-pyrrolyl) ketones. A detailed mechanistic study confirmed the involvement of enolether as a reaction intermediate. Several postsynthetic modifications along with easy access to β-carboline, tryptamines, tryptophols, and spiro-indolenine proclaim the synthetic utility of this powerful building block. On the basis of this concept, functionalized carbazoles were constructed by a cascade annulation strategy.
- Banerjee, Ankush,Maji, Modhu Sudan
-
p. 11521 - 11527
(2019/08/16)
-
- Acyclic Stereocontrol in the Additions of Nucleophilic Alkenes to α-Chiral N-Sulfonyl Imines
-
Diastereoselective Lewis acid-mediated additions of nucleophilic alkenes to N-sulfonyl imines are reported. The canonical polar Felkin–Anh model describing additions to carbonyls does not adequately describe analogous additions to N-sulfonyl imines. Herei
- Moore, Lucas C.,Lo, Anna,Fell, Jason S.,Duong, Matthew R.,Moreno, Jose A.,Rich, Barry E.,Bravo, Martin,Fettinger, James C.,Souza, Lucas W.,Olmstead, Marilyn M.,Houk, Kendall N.,Shaw, Jared T.
-
p. 12214 - 12220
(2019/08/26)
-
- Efficient Stereoselective Synthesis of a Key Chiral Aldehyde Intermediate in the Synthesis of Picolinamide Fungicides
-
A highly stereoselective and efficient synthesis of (4S,5S,6S)-6-(benzyloxy)-5-phenoxy-4-propoxyheptanal, a key intermediate for syntheses of picolinamide fungicides, is described in this report. The synthesis features a scalable allylpropyl ether preparation, an efficient synthesis of the C1-C3 anti,syn-(S,S,S) stereotriad via a highly diastereoselective allylboration, and Cu-catalyzed phenylation of a sterically hindered secondary alcohol with BiPh3(OAc)2 followed by highly regioselective hydroformylation with the formation of a linear aldehyde. Excellent overall route efficiency was achieved (six steps and 39% yield) starting from readily available and inexpensive (S)-ethyl lactate.
- Li, Fangzheng,Good, Steffen,Tulchinsky, Michael L.,Whiteker, Gregory T.
-
p. 2253 - 2260
(2019/10/16)
-
- Synthetic method of (S)-N'-(2-benzyloxy propylidene)formhydrazide
-
Disclosed is a synthetic method of (S)-N'-(2-benzyloxy propylidene)formhydrazide. The method includes the following steps: firstly, (S)-2-benzyloxy propionic acid with an acylation reagent to obtain (S)-2-benzyloxy propionyl chloride; and adding a palladi
- -
-
Paragraph 0034; 0036; 0041; 0043; 0046; 0048
(2019/05/08)
-
- A (S)-2 - benzyloxy propionaldehyde synthetic method (by machine translation)
-
A (S)- 2 - benzyloxy-propionic aldehyde synthesis method, the method for synthesis of the specific step includes: (1) the first (S)- 2 - animal pen oxygen radical propionic acid with an acylating reagent reaction, to obtain (S)- 2 - [...]; (2) then the pa
- -
-
Paragraph 0029; 0031; 0032; 0035; 0037-0039; 0041; 0042
(2019/05/08)
-
- Method for synthesizing N'-[(2S, 3S)-2-(benzyloxy) pentyl-3-base] formylhydrazine
-
A method for synthesizing N'-[(2S, 3S)-2-(benzyloxy) pentyl-3-base] formylhydrazine comprises the following steps: reacting (S)-2-benzyloxypropionic acid with an acylation reagent to obtain (S)-2-benzyloxy propionyl chloride; adding a palladium barium sulfate catalyst into o-xylene and reacting in hydrogen atmosphere for 15-30 min; adding (S)-2-benzyloxy propionyl chloride hydrogen atmosphere forreflux reaction until hydrogen is not absorbed; after the reaction is finished, the catalyst is filtered and the o-xylene is removed to obtain (S)-2-benzyloxypropionaldehyde; reacting the (S)-2-benzyloxypropionaldehyde with formylhydrazine, removing the solvent after finishing the reaction, and post-treating to obtain (S)-N'-(2 benzyloxypropyl) formylhydrazine; reacting the (S)-N'-(2 benzyloxypropyl) formylhydrazine with a Grignard reagent, and post-treating to obtain N'-((2s,3s)- 2-(benzyloxy) pentyl-3-base] formylhydrazine. According to the invention, an acylating reagent which is low in price and safer and more environment-friendly in reaction and a palladium barium sulfate catalyst which can be recycled for a plurality of times are used as reaction raw materials, so that the reaction process more conforms to the principle of atom economy, and the reaction is milder.
- -
-
Page/Page column 6-9
(2019/06/27)
-
- Method of synthesizing (S)-N'-(2-benzyloxy propylidene) formylhydrazine
-
The invention discloses a method of synthesizing (S)-N'-(2-benzyloxy propylidene) formylhydrazine. The method comprises the steps of: (1) allowing (S)-2-benzyloxy propionic acid and ethidene diamine to react to form (S)-2-(1-benzyloxy ethyl)-4,5-dihydro-1
- -
-
Paragraph 0012; 0028; 0030; 0032; 0034
(2018/07/30)
-
- Method for synthesizing N'-[(2S,3S)-2-(benzyloxy) penta-3-yl]formhydrazide
-
The invention discloses a method for synthesizing N'-[(2S,3S)-2-(benzyloxy) penta-3-yl]formhydrazide, comprising the following steps: letting (S)-2-benzyloxy propionic acid react with ethene diamine to obtain (S)-2-(1-benzyloxyethyl)-4,5-dihydro-1H-imidazole; adding metallic sodium into (S)-2-(1-benzyloxyethyl)-4,5-dihydro-1H-imidazole under the protection of nitrogen, stirring and reacting and processing to obtain (S)-2-benzyloxy propionaldehyde; letting (S)-2-benzyloxy propionaldehyde react with formhydrazide and carrying out post-treatment to obtain (S)-N'-(2-benzyloxy propylidene)formhydrazide; letting (S)-N'-(2-benzyloxy propylidene)formhydrazide react with a Grignard reagent and carrying out post-treatment after the reaction so as to obtain the product N'-[(2S,3S)-2-(benzyloxy)penta-3-yl]formhydrazide. The method of the invention has the following advantages: no expensive and unsafe organo-aluminum compound is used; preparation cost is low; post-treatments are simple; and operation is simple.
- -
-
Paragraph 0012; 0032; 0034; 0039
(2018/10/19)
-
- Posaconazole impurities and preparation method and use thereof
-
The invention discloses Posaconazole impurities, for example 4c shown in the description (PG is a hydroxyl protective group). Meanwhile, the invention further discloses a preparation method and use ofthe impurities.
- -
-
Paragraph 0164-0166
(2018/09/08)
-
- BENZAMIDE COMPOUNDS AS ROR GAMMA MODULATORS
-
The present disclosure is directed to compounds of formula (I) and pharmaceutically acceptable salts thereof, wherein ring A, R1, R2, R3, R4, R5, n and p are as defined herein, which are active as modulators of retinoid-related orphan receptor gamma t (RORγt). These compounds prevent, inhibit, or suppress the action of RORγt and are therefore useful in the treatment of RORγt mediated diseases, disorders, syndromes or conditions such as, e.g., pain, inflammation, COPD, asthma, rheumatoid arthritis, colitis, multiple sclerosis, psoriasis, neurodegenerative diseases and cancer.
- -
-
-
- Process for the Preparation of Triazole Antifungal Drug, Its Intermediates and Polymorphs Thereof
-
A process for the preparation of 4-[4-[4-[4-[[(3R,5R)-5-(2,4-difluorophenyl)tetrahydro-5-(1H-1,2,4-triazol-1-ylmethyl)-3-furanyl]methoxy]phenyl]-1-piperazinyl]phenyl]-2-[(1S,2S)-1-ethyl-2-hydroxypropyl]-2,4-dihydro-3H-1,2,4-triazol-3-one compound of formula-1, its intermediates and polymorphs thereof. (I)
- -
-
-
- First enantioselective total synthesis of penicimarin B, aspergillumarins A and B
-
A convergent enantioselective synthesis of penicimarin B, aspergillumarin A and B has been reported using Brown's allylation, DeBrabander-Bhattacharjee lactonization and Grubbs cross coupling metathesis. During this synthesis we have standardized the conditions for DeBrabande-Bhattacharjee lactonization to obtain excellent yield (>90%).
- Yadav, Jhillu Singh,Mishra, Anand Kumar,Dachavaram, Soma Shekar,Ganesh Kumar,Das, Saibal
-
supporting information
p. 2921 - 2923
(2014/05/06)
-
- Stereoselective synthesis of C19-C27 fragment of bryostatin 11
-
A convergent synthesis of C19-C27 fragment (2) of bryostatin-11 is described. The key steps involved in this approach are kinetic resolution, Grignard reaction, and Sharpless dihydroxylation. AIBN catalyzed radical cyclization strategy has been used for the first time to construct the six-membered pyran system.
- Yadav,Swamy,Subba Reddy,Ravinder
-
supporting information
p. 4054 - 4056
(2014/07/22)
-
- Stereoselective synthesis of C19-C27 fragment of bryostatin 11
-
A convergent synthesis of C19-C27 fragment (2) of bryostatin-11 is described. The key steps involved in this approach are kinetic resolution, Grignard reaction, and Sharpless dihydroxylation. AIBN catalyzed radical cyclization strategy has been used for the first time to construct the six-membered pyran system.
- Yadav,Swamy,Subba Reddy,Ravinder
-
supporting information
p. 4054 - 4056
(2015/02/02)
-
- Toward the synthesis of (+)-peloruside A via an intramolecular vinylogous aldol reaction
-
The use of the intramolecular vinylogous aldol reaction for the preparation of an advanced intermediate for the synthesis of peloruside A is described. The reaction was applied to compound 19 and proceeds in high yield and good levels of diastereoselectiv
- Gazaille, Jeffrey A.,Abramite, Joseph A.,Sammakia, Tarek
-
p. 178 - 181
(2012/03/08)
-
- 2,3,6-Trideoxy sugar nucleotides: Synthesis and stability
-
The synthesis and characterization of highly challenging 2,3,6-trideoxy sugar nucleotides were described for the first time. The study of their hydrolysis kinetics in aqueous buffers provided insight into their application as glycosyl donors.
- Wu, Mingxuan,Meng, Qingqing,Ge, Min,Bai, Linquan,Zhou, Huchen
-
p. 5799 - 5801
(2011/12/14)
-
- Synthetic approaches to the bottom half fragment for bryostatin 11
-
An approach towards the stereoselective synthesis of the bottom half fragment of bryostatin 11 is described. Key steps -include asymmetric aldol and Saksena-Evans reduction reactions -to construct multiple stereogenic centers and thioketalization-lactoniz
- Nakagawa-Goto, Kyoko,Crimmins, Michael T.
-
p. 1555 - 1558
(2011/08/05)
-
- Stereoselective direct amine-catalyzed decarboxylative aldol addition
-
A stereoselective decarboxylative aldol addition of β- and α-keto acids in the presence of catalytic amounts of amines is described. By the optional deployment of chiral enolizable aldehydes an access to enantiopure configurative defined ketopentoses, ketohexoses, or ketoheptoses is given.
- Rohr, Kerstin,Mahrwald, Rainer
-
supporting information; experimental part
p. 1878 - 1880
(2011/06/20)
-
- A concise asymmetric synthesis of (-)-hongconin and (-)-1-epi-hongconin
-
A concise asymmetric synthesis of (-)-hongconin and (-)-1epi-hongconin is described. The synthesis features an efficient combination of Doetz benzannulation or lactaldehyde arylation and the oxa-Pictet-Spengler reaction as the key steps. The synthesis is
- Fernandes, Rodney A.,Chavan, Vijay P.
-
experimental part
p. 4306 - 4311
(2010/10/19)
-
- Stereoselective synthesis (+)-cephalosporolide D
-
A simple and efficient stereoselective synthesis of macrolactone, (+)-cephalosporolide D has been accomplished in 13 steps from inexpensive and commercially available starting materials in an overall yield of 17%, respectively. This convergent synthesis u
- Reddy, G. Venkateswar,Kumar, R. Sateesh Chandra,Sreedhar, Eppakayala,Babu, K. Suresh,Rao, J. Madhusudana
-
scheme or table
p. 1723 - 1726
(2010/05/03)
-
- Alkylation and aldol reactions of acyl derivatives of N-1-(1′-naphthyl)ethyl-O-tert-butylhydroxylamine: asymmetric synthesis of α-alkoxy-, α-substituted-β-alkoxy- and α,β-dialkoxyaldehydes
-
Treatment of a range of O-protected glycolate derivatives of the chiral auxiliary N-1-(1′-naphthyl)ethyl-O-tert-butylhydroxylamine with KHMDS in the presence of 18-crown-6 followed by addition of an alkyl halide generates α-substituted derivatives with very high levels of diastereoselectivity. Alternatively, reaction of the potassium enolate of a propanoate or O-protected glycolate derivative of N-1-(1′-naphthyl)ethyl-O-tert-butylhydroxylamine with a range of aldehydes gives syn-aldol products with high levels of diastereoselectivity. These adducts may be reductively cleaved with LiAlH4 to give enantiopure α-alkoxy-, α-substituted-β-alkoxy- and α,β-dialkoxyaldehydes in good yield.
- Chernega, Alexander N.,Davies, Stephen G.,Fletcher, Ai M.,Goodwin, Christopher J.,Hepworth, David,Prasad, R. Shyam,Roberts, Paul M.,Savory, Edward D.,Smith, Andrew D.,Thomson, James E.
-
experimental part
p. 4167 - 4194
(2010/07/06)
-
- Highly diastereoselective α-hydroxylation of fox chiral auxiliary-based amide enolates with molecular oxygen
-
"Figure Presented" Using a trifluoromethylated oxazolidine (Fox) chiral auxiliary, the hydroxylation reaction of enolates was very efficiently performed under smooth and friendly conditions with molecular oxygen as oxidizer. This reaction occurred with an extremely high diastereoselectivlty. After cleavage, the chlral auxiliary Is efficiently recovered and highly valuable enantlopure oxygenated carboxylic acids and alcohols are released.
- Lubin, Hodney,Tessier, Arnaud,Chaume, Gregory,Pytkowicz, Julien,Brigaud, Thierry B.
-
supporting information; experimental part
p. 1496 - 1499
(2010/07/03)
-
- BRYOSTATIN ANALOGUES, SYNTHETIC METHODS AND USES
-
Biologically active compounds related to the bryostatin family of compounds, having simplified spacer domains and/or improved recognition domains are disclosed, including methods of preparing and utilizing the same.
- -
-
Page/Page column 79
(2009/05/28)
-
- BRYOSTATIN ANALOGUES, SYNTHETIC METHODS AND USES
-
Biologically active compounds related to the bryostatin family of compounds, including methods of utilizing the same.
- -
-
Page/Page column 57
(2009/10/31)
-
- Effect of substituents on the ring-closing metathesis reaction in the synthesis of functionalized nonanolactones
-
The synthesis of functionalized nine-membered ring lactones based on sequential esterification and ring-closing metathesis (RCM) reactions is reported. The effects of olefin substitution and allylic and homoallylic oxygenated substituents on the RCM react
- Ramírez-Fernández, Jacinto,Collado, Isidro G.,Hernández-Galán, Rosario
-
p. 339 - 342
(2008/09/17)
-
- A stereoselective approach for the total synthesis of clonostachydiol
-
A stereoselective synthesis of clonostachydiol is accomplished using readily available (±)-epichlorohydrin as a precursor. The synthesis involves direct and straightforward reactions such as Sharpless asymmetric epoxidation, iodination, stereoselective op
- Yadav,Swamy,Subba Reddy
-
scheme or table
p. 2773 - 2776
(2009/04/16)
-
- Total synthesis of GEX1A
-
(Chemical Equation Presented) An efficient and readily modifiable synthesis of GEX1A/herboxidiene/TAN-1609 (1) was developed. This modular synthesis featured a Suzuki coupling to install the conjugated diene and a Ru-catalyzed lactonization and Roush crotylation to construct the functionalized tetrahydropyran moiety. Myers' alkylation, cross-metathesis, and Keck crotylation were employed for assembly of the biologically essential side-chain domain.
- Murray, Timothy J.,Forsyth, Craig J.
-
supporting information; experimental part
p. 3429 - 3431
(2009/05/11)
-
- Regio- and stereoselective nickel-catalyzed homoallylation of aldehydes with 1,3-dienes
-
Ni(acac)2 catalyzes homoallylation of aldehydes with 1,3-dienes in the presence of triethylborane. Triethylborane serves as a reducing agent delivering a formal hydride to the C2 position of 1,3-dienes, thus generating a formal homoallyl anion species and enabling the novel homoallylation of aldehydes. The reaction proceeds smoothly at room temperature in the absence of any phosphane or nitrogen ligands and is highly regioselective and stereoselective for a wide variety combination of aldehydes and 1,3-dienes: e.g., isoprene and benzaldehyde combine to give a mixture of anti- and syn-1-phenyl-3-methyl-4-penten-1-ol (2.2) in a ratio of 15:1 in 90% yield. Under the conditions, sterically congested aliphatic aldehydes and ketones show low yields. In such cases, diethylzinc serves as a substitute for triethylborane and yields the expected products in good yields with similarly high regio- and stereoselectivity. 1,3-Cyclohexadiene is one exception among 24 kinds of dienes examined and undergoes allylation (not homoallylation) selectively.
- Kimura, Masanari,Ezoe, Akihiro,Mori, Masahiko,Iwata, Keisuke,Tamaru, Yoshinao
-
p. 8559 - 8568
(2007/10/03)
-
- Glycosidation via conjugate addition of anomeric alkoxides to nitroalkenes and nitrosoalkenes
-
The conjugate addition reactions of protected pyranose alkoxides to both nitroalkenes and nitrosoalkenes, as a route to 2-nitroalkyl, 2-oximinoalkyl and 2-oxoalkyl glycosides, are described.
- Trewartha, Gary,Burrows, Jeremy N.,Barrett, Anthony G. M.
-
p. 3553 - 3556
(2007/10/03)
-
- A highly stereoselective ether directed palladium catalysed aza-Claisen rearrangement
-
A highly stereoselective rearrangement of allylic trichloroacetimidates to allylic trichloroamides has been achieved using adjacent ether groups to direct facial coordination of the palladium(II) catalyst. The Royal Society of Chemistry 2005.
- Jamieson, Andrew G.,Sutherland, Andrew
-
p. 735 - 736
(2007/10/03)
-
- The use of nonactivated iminodienophiles in the stereoselective aza-Diels-Alder reaction
-
This paper describes the preparation of nitrogen-containing bicycles by the aza-Diels-Alder reaction of nonactivated iminodienophiles and cyclopentadiene. Readily available starting materials such as (S)-(-)-lactate and L-amino acids were used for the pre
- Trifonova, Anna,Andersson, Pher G.
-
p. 445 - 452
(2007/10/03)
-
- Stereoselective synthesis of functionalised triol units by SnCl4 promoted allylation of α-benzyloxyaldehydes: Crucial role of the stoichiometry of the Lewis acid
-
Enantiomerically pure syn-anti and syn-syn configured triol units are efficiently synthesized by the SnCl4 mediated allylation of chiral α-benzyloxyaldehydes with the uniquely functionalised allylstannane 9. Remarkably, the stereochemistry of t
- Dubost, Christophe,Leroy, Bernard,Markó, Istvan E.,Tinant, Bernard,Declercq, Jean-Paul,Bryans, Justin
-
p. 7693 - 7704
(2007/10/03)
-
- Stereoselective Grignard additions to N-formyl hydrazone: A concise synthesis of NoxafilR side chain and a synthesis of Noxafil R
-
Addition of ethyl Grignard reagent to the formyl hydrazone 11 via in situ silylation provided the corresponding formyl hydrazine with excellent diastereoselectivity in favor of the desired S,S-diastereoisomer 6. Treatment of 6 with the phenyl carbamate 13 efficiently provided the O-benzyl protected Noxafil, which was deprotected to provide NoxafilR.
- Saksena, Anil K.,Girijavallabhan, Viyyoor M.,Wang, Haiyan,Lovey, Raymond G.,Guenter, Frank,Mergelsberg, Ingrid,Puar, Mohinder S.
-
p. 8249 - 8251
(2007/10/03)
-
- Concise formal synthesis of the bryostatin southern hemisphere (C17-C27)
-
An efficient synthesis of Hale and co-workers' C17-C27 bryostatin southern hemisphere intermediate has been accomplished in six steps and 33% overall yield from (R)-2-(benzyloxy)propanal. The synthesis features a one-pot DIBALH/HWE ester homologation as w
- Voight, Eric A.,Roethle, Paul A.,Burke, Steven D.
-
p. 4534 - 4537
(2007/10/03)
-
- Stereoselective chloroacetate aldol reactions: Syntheses of acetate aldol equivalents and darzens glycidic esters
-
Aldol reaction of the Ti-enolate derived from cis-1-tosylamido-2-indanyl chloroacetate with representative aldehydes proceeded in excellent yield and high diastereoselectivities. Removal of chlorine provided alternative access to highly diastereoselective acetate aldol equivalents or the corresponding glycidic ester condensation products.
- Ghosh, Arun K.,Kim, Jae-Hun
-
p. 2725 - 2728
(2007/10/03)
-
- A Synthesis of L-Vancosamine Derivatives from Non-Carbohydrate Precursors by a Short Sequence Based on the Marshall, McDonald, and Du Bois Reactions
-
(Matrix presented). The carbamate-protected L-vancosamine glycal, viewed as a universal precursor for vancosamine derivatives, was prepared by a short scheme based on diastereoselective addition of an allenyl stannane to a lactaldehyde ether, the tungsten
- Parker, Kathlyn A.,Chang, Wonsuk
-
p. 3891 - 3893
(2007/10/03)
-
- Imidazole compounds
-
Imidazole compounds having adenosine deaminase inhibitory activity represented by formula (I) wherein R1is hydrogen, hydroxy, protected hydroxy, or aryl optionally substituted with suitable substituent(s); R2is hydrogen or lower alkyl; R3is hydroxy or protected hydroxy; R4is cyano, (hydroxy)iminoamino(lower)alkyl, carboxy, protected carboxy, heterocyclic group optionally substituted with amino, or carbamoyl optionally substituted with suitable substituent(s); and —A— is —Q— or —O—Q—, wherein Q is single bond or lower alkylene, provided that when R2is lower alkyl, then R1is hydroxy, protected hydroxy, or aryl optionally substituted with suitable substituent(s), its prodrug, or their salt. The compounds are useful for treating and/or preventing diseases for which adenosine is effective.
- -
-
Page column 10
(2008/06/13)
-
- Enantioselective epoxidation with chiral MnIII(salen) catalysts: Kinetic resolution of aryl-substituted allylic alcohols
-
A set of aryl-substituted allylic alcohols rac-2 has been epoxidized by chiral Mn(salen*) complexes 1 as the catalyst and iodosyl benzene (PhIO) as the oxygen source. Whereas one enantiomer of the allylic alcohol 2 is preferentially epoxidized to give the threoor cis-epoxy alcohol 3 (up to 80% ee) as the main product (dr up to >95:5), the other enantiomer of 2 is enriched (up to 53% ee). In the case of 1,1-dimethyl-1,2-dihydronaphthalen-2-ol (2c), the CH oxidation to the enone 4c proceeds enantioselectively and competes with the epoxidation. The absolute configurations of the allylic alcohols 2 and their epoxides 3 have been determined by chemical correlation or CD spectroscopy. The observed diastereo- and enantioselectivities in the epoxidation reactions are rationalized in terms of a beneficial interplay between the hydroxy-directing effect and the attack along the Katsuki trajectory.
- Adam,Humpf,Roschmann,Saha-Moeller
-
p. 5796 - 5800
(2007/10/03)
-
- General asymmetric hydrogenation of hetero-aromatic ketones
-
(matrix presented) Het = hetero-aromatic ring (R,R)-Ru cat = trans-RuCl2[(R)-xylbinap][(R)-daipen] trans-RuCl2[(R)-xylbinap][(R)-daipen] or the S,S complex acts as an efficient catalyst for asymmetric hydrogenation of hetero-aromatic ketones. The hydrogenation proceeds with a substrate-to-catalyst molar ratio of 1000-40000 to give chiral alcohols in high ee and high yield. The enantioselectivity appears to be little affected by the properties of the hetero-aromatic ring. This method allows for asymmetric synthesis of duloxetine, an inhibitor of serotonin and norepinephrine uptake carriers.
- Ohkuma, Takeshi,Koizumi, Masatoshi,Yoshida, Makoto,Noyori, Ryoji
-
p. 1749 - 1751
(2007/10/03)
-
- Total synthesis of motuporin (nodularin-v)
-
The serine/threonine phosphatase (protein phosphatase 1 and 2A) inhibitors constitute a biologically and structurally interesting class of natural products. Among this class of inhibitors are cyclic pentapeptides (nodularins) and cyclic heptapeptides (mic
- Bauer, Shawn M.,Armstrong, Robert W.
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p. 6355 - 6366
(2007/10/03)
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- Activation of the reverse-cope elimination by allylic oxygen functions: Syntheses of (-)-hygroline and (+)-pseudohygroline
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Reverse-Cope cyclisations of N-(4-alkenyl)hydroxylamines 8 are accelerated by the presence of the allylic oxygen function; this has been applied to a brief synthesis of the alkaloids (-)-hygroline 6 and (+)- pseudohygroline 7.
- Knight, David W.,Salter, Rhys
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p. 5915 - 5918
(2007/10/03)
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- Diastereoselective synthesis of enantiopure 5-[2-(alkoxyalkyl)-1- (hydroperoxypropyl)]-3-alkoxycarbonyl-2-alkyl furans
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The diastereoselective approach to enantiomerically pure furyl hydroperoxides of general type 1 has been accomplished starting from (S)-(- )-ethyl lactate. In the first part of the synthesis the alkylating reagents 7a,b were efficiently produced to be use
- Lattanzi, Alessandra,Sagulo, Francesco,Scettri, Arrigo
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p. 2023 - 2035
(2007/10/03)
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