Category: 617-55-0

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

Mattingly, Stephanie J.; Wuest, Frank; Schirrmacher, Ralf published the artcile< Synthesis of 2-Fluoroacetoacetic Acid and 4-Fluoro-3-hydroxybutyric Acid>, Formula: C6H10O5, the main research area is fluoroacetoacetic acid preparation; acetoacetate ester fluorination; fluoro hydroxybutyric acid preparation; epoxyester fluorination.

The synthesis of two new fluorinated butyric acids (and three related esters) these were derivatives of the metabolites acetoacetic acid and 3-hydroxybutyric acid. 4-Fluoro-3-hydroxybutyric acid was synthesized from epoxy ester precursors via ring opening by triethylamine trihydrofluoride. 2-Fluoroacetoacetic acid was prepared by electrophilic fluorination of an acid-labile β-keto ester. The gradual pH-dependent decarboxylation of 2-fluoroacetoacetic acid was investigated by 19F NMR spectroscopy.

Synthesis published new progress about Acid halides Role: SPN (Synthetic Preparation), PREP (Preparation). 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

Tsai, Cheng-Che; Chuang, Wei-Tsung; Tsai, Yow-Fu; Li, Jyun-Ting; Wu, Yu-Fa; Liao, Chun-Chen published the artcile< Intra- and intermolecular hydrogen bonds enhance the fluoride-responsiveness of functionalized glycolipid-based gelators>, Application In Synthesis of 617-55-0, the main research area is glycolipid preparation supramol gel assembly hydrogen bond fluoride.

The authors propose a facile approach toward enhancing the efficiency of fluoride-responsive gels through the positioning of functionalized receptor units, allowing tunable intra- and intermol. hydrogen bonding, in the gelator mols. The authors have prepared the new glycolipid-based gelator 2 and its hydroxy and methoxy derivatives 2a and 2b, resp., to study the effects of three types modes of supramol. assembly: solely intermol. hydrogen bonding in 2, solely intramol. hydrogen bonding in 2b, and both inter- and intramol. hydrogen bonding in 2a. 1H NMR spectra confirmed the self-assembly interactions of these glycolipid-based gelators. The authors measured the min. gel concentrations and sol-gel transitions and recorded x-ray diffraction patterns and electron micrographs to characterize the gelation behavior and structural organization of each of these supramol. gels. Among these three gelators, only 2 and 2a could form organogels in the test solvents, indicating that intermol. hydrogen bonding plays a determinant role in the supramol. assemblies leading to gelation. The self-assembly of 2 resulted in a bilayer-packed lamellar structure within ribbon-like fibers, whereas that of 2a resulted in hexagonally packed cylindrical micelles within tree-like fibers. A min. amount of 0.3 equiv of F- was required for complete disruption of the gel formed from 2a, which was approx. four times lower than that required for the gel formed from 2. Thus, the incorporation of a β-hydroxy motif-the only difference in the chem. structures of 2 and 2a-led to interesting variations in the resulting gel morphologies and enhanced the gel’s fluoride-responsiveness.

Journal of Materials Chemistry B: Materials for Biology and Medicine published new progress about Gelation. 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

Zhang, Junjie; Wang, Huanxia; Ma, Yun; Wang, Youming; Zhou, Zhenghong; Tang, Chuchi published the artcile< CaF2 catalyzed SN2 type chlorodehydroxylation of chiral secondary alcohols with thionyl chloride: a practical and convenient approach for the preparation of optically active chloroalkanes>, Category: esters-buliding-blocks, the main research area is chloroalkane chiral preparation; calcium fluoride catalyst chlorodehydroxylation chiral secondary alc thionyl chloride.

A CaF2 catalyzed chlorodehydroxylation of chiral secondary alcs. with thionyl chloride has been developed. The chlorination reaction is effective for a wide range of alcs., generating the corresponding chloroalkanes in good yield with high optical purity with inversion of the original configuration of the alc.

Tetrahedron Letters published new progress about Chlorination. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Category: esters-buliding-blocks.

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

Dinca, Emanuela; Hartmann, Philip; Smrcek, Jakub; Dix, Ina; Jones, Peter G.; Jahn, Ullrich published the artcile< General and Efficient α-Oxygenation of Carbonyl Compounds by TEMPO Induced by Single-Electron-Transfer Oxidation of Their Enolates>, Formula: C6H10O5, the main research area is alpha oxygenated carbonyl compound preparation; regioselective oxygenation carbonyl compound single electron transfer oxidation; stable free radical TEMPO coupling carbonyl compound; piperidinyloxy ketone ester amide acid nitrile preparation; enolate aggregate influence oxygenation reactions significantly; chemoselective reduction piperidinyloxy compound; hydroxy alpha carbonyl compound preparation; monoprotected diol preparation; amino alc protected preparation.

A generally applicable method for the synthesis of protected α-oxygenated carbonyl compounds is reported. It is based on the single-electron-transfer oxidation of easily generated enolates to the corresponding α-carbonyl radicals. Coupling with the stable free radical TEMPO provides α-(piperidinyloxy) ketones, esters, amides, acids or nitriles in moderate-to-excellent yields. Enolate aggregates influence the outcome of the oxygenation reactions significantly. Competitive reactions have been analyzed and conditions for their minimization are presented. Chemoselective reduction of the products led to either N-O bond cleavage to α-hydroxy carbonyl compounds or reduction of the carbonyl functionality to monoprotected 1,2-diols or O-protected amino alcs.

European Journal of Organic Chemistry published new progress about Aldehydes Role: RCT (Reactant), RACT (Reactant or Reagent) (enolization and TEMPO-induced single-electron-transfer oxidation of). 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

Listowsky, Irving; Avigad, Gad; Englard, Sasha published the artcile< Conformational equilibria and stereochemical relations among carboxylic acids>, HPLC of Formula: 617-55-0, the main research area is acyclic acid conformation; conformation acyclic acid; circular dichroism acyclic acid.

The CO spectra of certain acyclic carboxylic acids were surveyed in an effort to study their conformation in solution In aqueous solution the spectra of many α-hydroxy acids were characterized by two overlapping ellipticity bands; a weak one in the 240-mμ spectral region and a more intense one of opposite sign near 210 mμ. At elevated temperatures or in solvents of low dielec. constant, the band of longer wavelength increased in intensity with an attendant decrease in the short-wavelength band. These properties are compatible with the presence of two structural species in equilibrium, and could be related to the contributions of specific rotational isomers of the acids. Conformations with the hydroxyl and carbonyl groups in an eclipsed alignment are designated as preferred. In contrast to the α-hydroxy acids, carboxylic acids with α-alkyl substituents generally showed only a single dichroic band centered near 210 mμ. In general, coplanarity of the carboxyl group and α-substituents was assumed, and interpretations in terms of the preferred orientation of substituents adjacent to the carboxyl group are suggested. The proposed population of rotational isomers was consistent with the observed effects of solvent polarity, temperature, polarity of substituents, and predicted steric interactions. An empirical rule relating the sign of ellipticity and the conformation of these classes of carboxylic acids was applied.

Journal of Organic Chemistry published new progress about Acids Role: PRP (Properties). 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

Muraoka, Osamu; Toyooka, Naoki; Ohshima, Yumiko; Narita, Norihiko; Momose, Takefumi published the artcile< Synthesis of natural (S)-(-)-tulipalin B starting from L-malic acid as a chiral pool>, Recommanded Product: (S)-Dimethyl 2-hydroxysuccinate, the main research area is tulipalin B total synthesis enantioselectivity; malic acid chiral synthon tulipalin B.

Naturally occurring tulipalin B (I) was prepared enantioselectively from chiral synthon L-malic acid (II) in 15% yield.

Heterocycles published new progress about Chiral synthons. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Recommanded Product: (S)-Dimethyl 2-hydroxysuccinate.

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