Category: 617-55-0

Pommier, Agnes; Pons, Jean-Marc; Kocienski, Philip J. published the artcile< The First Total Synthesis of (-)-Lipstatin>, Electric Literature of 617-55-0, the main research area is asym synthesis lipstatin; stereoselective cycloaddition silylketene tetradecadienal.

A key step in the first total synthesis of the potent pancreatic lipase inhibitor (-)-lipstatin (I) is a diastereoselective Lewis acid-promoted [2 + 2] cycloaddition reaction between (trimethylsilyl)ketene Me(CH2)5C(SiMe3):CO and tetradecadienal II (TBS = Me3CSiMe2), which is prepared from di-Me (S)-(-)-malate.

Journal of Organic Chemistry published new progress about [2+2] Cycloaddition reaction. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Electric Literature of 617-55-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Nagano, Masanobu; Tanaka, Masakazu; Doi, Mitsunobu; Demizu, Yosuke; Kurihara, Masaaki; Suemune, Hiroshi published the artcile< Helical-Screw Directions of Diastereoisomeric Cyclic α-Amino Acid Oligomers>, HPLC of Formula: 617-55-0, the main research area is oligomer cyclic amino acid diastereomer preparation helical secondary structure.

Two series of homooligomers composed of diastereoisomeric cyclic α-amino acids having two chiral centers at the α-carbon and the side chain were synthesized, and their preferred secondary structures were studied in solution and in the crystal state. The oligomers are a new class of helical-foldamers possessing two kinds of chiral centers on the helical backbone and at the lateral surface of the helix.

Organic Letters published new progress about Crystal structure. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, HPLC of Formula: 617-55-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Aponick, Aaron; Li, Chuan-Ying; Palmes, Jean A. published the artcile< Au-Catalyzed cyclization of monopropargylic triols: an expedient synthesis of monounsaturated spiroketals>, Computed Properties of 617-55-0, the main research area is spiroketal derivative preparation; monopropargylic triol preparation cyclization gold; gold cyclization catalyst.

The gold-catalyzed cyclization of monopropargylic triols to form olefin-containing spiroketals is reported. The reactions are rapid and high yielding when 2 mol % of the catalyst generated in situ from Au[P(t-Bu)2(o-biphenyl)]Cl and AgOTf is employed in THF at 0 °C. A range of differentially substituted triols leading to substituted 5- and 6-membered ring spiroketals were prepared and function well in the reaction.

Organic Letters published new progress about Cyclization. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Computed Properties of 617-55-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Clark, J. Stephen; Fessard, Thomas C.; Wilson, Claire published the artcile< A Concise and Stereoselective Synthesis of the A-Ring Fragment of the Gambieric Acids>, Formula: C6H10O5, the main research area is asym synthesis gambieric acid ring fragment rearrangement oxonium ylide.

The A-ring fragment I of the gambieric acids has been prepared by a short and efficient route. The key 3(2H)-furanone intermediate has been obtained by [2,3] rearrangement of an allylic oxonium ylide generated from intramol. reaction of a crotyl ether with a copper carbenoid. A single stereogenic center has been set by using a chiral pool starting material and the other three have been established by using highly diastereoselective substrate-controlled transformations.

Organic Letters published new progress about Rearrangement ([2,3]-rearrangement). 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Formula: C6H10O5.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Sartori, G.; Maggi, R. published the artcile< Carboxylic acid esters: product subclass 16: 3-heteroatom-substituted alkanoic acid esters>, COA of Formula: C6H10O5, the main research area is review heteroatom substituted alkanoic acid ester preparation organic synthesis; beta heteroatom substituted carboxylic acid ester preparation review.

A review of methods to prepare 3-heteroatom-substituted alkanoic acid esters.

Science of Synthesis published new progress about Carboxylic esters Role: SPN (Synthetic Preparation), PREP (Preparation) (β-heteroatom-substituted). 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, COA of Formula: C6H10O5.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Prasanth, C. P.; Joseph, Ebbin; Abhijith, A.; Nair, D. S.; Ibnusaud, Ibrahim; Raskatov, Jevgenij; Singaram, Bakthan published the artcile< Stabilization of NaBH4 in Methanol Using a Catalytic Amount of NaOMe. Reduction of Esters and Lactones at Room Temperature without Solvent-Induced Loss of Hydride>, COA of Formula: C6H10O5, the main research area is sodium borohydride methanol catalysis reduction ester lactone.

Rapid reaction of NaBH4 with MeOH precludes its use as a solvent for large-scale ester reductions We have now learned that a catalytic amount of NaOMe (5 mol %) stabilizes NaBH4 solutions in methanol at 25 °C and permits the use of these solutions for the reduction of esters to alcs. The generality of this reduction method was demonstrated using 22 esters including esters of naturally occurring chiral γ-butyrolactone containing dicarboxylic acids. This method permits the chemoselective reductions of esters in the presence of cyano and nitro groups and the reductive cyclization of a pyrrolidinedione ester to a fused five-membered furo[2,3-b]pyrrole and a (-)-crispine A analog in high optical and chem. yields. Lactones, aliphatic esters, aromatic esters containing electron-withdrawing groups, and heteroaryl esters are reduced more rapidly than aryl esters containing electron-donating groups. The 11B NMR spectrum of the NaOMe-stabilized NaBH4 solutions showed a minor quartet due to monomethoxyborohydride (NaBH3OMe) that persisted up to 18 h at 25 °C. We postulate that NaBH3OMe is probably the active reducing agent. In support of this hypothesis, the activation barrier for hydride transfer from BH3(OMe)- onto benzoic acid Me ester was calculated as 18.3 kcal/mol.

Journal of Organic Chemistry published new progress about Aliphatic esters Role: RCT (Reactant), RACT (Reactant or Reagent). 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, COA of Formula: C6H10O5.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

White, James D.; Lincoln, Christopher M.; Yang, Jongtae; Martin, William H. C.; Chan, David B. published the artcile< Total Synthesis of Solandelactones A, B, E, and F Exploiting a Tandem Petasis-Claisen Lactonization Strategy>, Application In Synthesis of 617-55-0, the main research area is solandelactone A B E F total synthesis; Petasis Claisen lactonization tandem total synthesis solandelactone; Nozaki Hiyama Kishi coupling total synthesis solandelactone; Simmons Smith cyclopropanation total synthesis solandelactone; methylenation Petasis total synthesis solandelactone.

Solandelactones A, B, E, and F I (R = α-OH, R1 = H; R = β-OH, R1 = H; R = α-OH, R12 = bond; R = β-OH, R12 = bond, resp.) were synthesized using Nozaki-Hiyama-Kishi coupling of iododiene (3S,1E,5Z)-ICH:CHCH(OH)CH2CH:CH(CH2)4Me with aldehydes II obtained by oxidation of the corresponding alcs. Key steps in the synthesis of the latter alcs. (i) a Nagao asym. acetate aldol reaction of aldehyde (E)-Me3CPh2SiOCH2CH:CHCHO with thionothiazolidine III to set in place an alc. that becomes the (7S) lactone center of solandelactones, (ii) a Simmons-Smith cyclopropanation of (3R,4E)-Me3CPh2SiOCH2CH:CHCH(OH)CH2CON(MeO)Me directed by this alc., and (iii) Petasis methylenation of cyclic carbonate IV in tandem with a Claisen rearrangement that generates the octenalactone portion of solandelactones. Synthesis of solandelactones A, B, E, and F confirmed their gross structure and absolute configuration at C7, 8, 10, and 14 but showed that alc. configuration at C11 must be reversed in pairs, A/B and E/F, from the previous assignment made to these hydroid metabolites. A biogenesis of solandelactones is proposed for these C22 oxylipins that parallels a hypothesis put forward previously to explain the origin of C20 cyclopropane-containing algal products.

Journal of Organic Chemistry published new progress about Aldol addition, stereoselective (Nagao). 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Application In Synthesis of 617-55-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Saito, Seiki; Ishikawa, Teruhiko; Kuroda, Akiyoshi; Koga, Kazuya; Moriwake, Toshio published the artcile< A revised mechanism for chemoselective reduction of esters with borane-dimethyl sulfide complex and catalytic sodium tetrahydroborate directed by adjacent hydroxyl group>, Related Products of 617-55-0, the main research area is ester reduction chemoselectivity borane dimethyl sulfide; sodium borohydride reduction ester stereochem; chiral synthon.

The plausible mechanism for the reduction of the ester groups with a strong preference for one located α to the hydroxyl groups of (S)-malates and (R,R)-tartrate-based derivatives has been proposed together with some results with regard to its applications to the synthesis of chiral synthons. Thus, reduction of di-Et (S)-maleate with BH3·SMe2 in THF in the presence of catalytic NaBH4 gave 97% Et (3S)-3,4-dihydroxybutanoate.

Tetrahedron published new progress about Chiral synthons. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Related Products of 617-55-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Zheng, Ying; Jia, Yimin; Yuan, Yuan; Jiang, Zhong-Xing; Yang, Zhigang published the artcile< F--Free Deoxyhydrotrifluoromethylation of α-Keto Esters with Ph3P+CF2CO2-: Synthesis of α-CF3-Substituted Esters>, Reference of 617-55-0, the main research area is deoxyhydrotrifluoromethylation keto ester fluoromethylating reagent.

Trifluoromethylated compounds are usually obtained via trifluoromethylation reaction by the use of CF3SiMe3 and NaSO2CF3, Umemoto’s and Togni’s reagents. Here, an external fluorine anion-free direct deoxyhydrotrifluoromethylation of α-keto esters with a difluoromethylating reagent has been achieved, in which the employment of water can promote the dissociation of the CF2 group to form a CF3 moiety, which provides the successful transformation. The current protocol demonstrates one of the most practical approaches to generate α-trifluoromethyl esters with a broad substrate scope and high functional group compatibility, in which it is applicable to late-stage modification of biol. active compounds and can be readily scaled up. Mechanistic investigation reveals that an in situ-generated gem-difluoroalkene intermediate is decomposed by water, giving rise to acid fluoride and HF.

Journal of Organic Chemistry published new progress about Atom economy (and step economy). 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Reference of 617-55-0.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Sasaki, Ryosuke; Tanabe, Yoo published the artcile< Chiral synthesis of methyl (R)-2-Sulfanylcarboxylic esters and acids with optical purity determination using HPLC>, Name: (S)-Dimethyl 2-hydroxysuccinate, the main research area is sulfanylcarboxylic ester acid preparation enantioselective cyclocondensation; thiazolidinone preparation diastereoselective; 2-sulfanylmandelic ester; 2-sulfanylsuccinic ester; HPLC analysis; SN2 inversion; drug discovery; process chemistry; thiazolidin-4-one; thiolactic acid.

Accessible chiral synthesis of 3 types of (R)-2-sulfanylcarboxylic esters and acids were performed: (R)-2-sulfanylpropanoic (thiolactic) ester (53%, 98% ee) and acid (39%, 96% ee), (R)-2-sulfanylsuccinic diester (59%, 96% ee) and (R)-2-mandelic ester (78%, 90% ee) and acid (59%, 96% ee). The present practical and robust method involves (i) clean SN2 displacement of methanesulfonates of (S)-2-hydroxyesters by using com. available AcSK with tris(2-[2-methoxyethoxy]ethyl)amine and (ii) sufficiently mild deacetylation. The optical purity was determined by the corresponding (2R,5R)-trans-thiazolidin-4-one and (2S,5R)-cis-thiazolidin-4-one derivatives based on accurate high-performance liquid chromatog. anal. with high-resolution efficiency. The Ti(O-i-Pr)4 catalyst promoted smooth trans-cyclocondensation of (R)-2-sulfanylcarboxylic esters with available N-(benzylidene)methylamine to afford (2R,5R)-trans-thiazolidin-4-ones under neutral conditions without any racemization, whereas (2S,5R)-cis-thiazolidin-4-ones were obtained via cis-cyclocondensation and no catalysts. Direct high-performance liquid chromatog. of Me (R)-mandelate was also performed; however, the resolution efficiency was inferior to that of the thaizolidin-4-one derivatizations.

Chirality published new progress about Cyclocondensation reaction. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Name: (S)-Dimethyl 2-hydroxysuccinate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics