Tag: M.W=150-200

Takano, Seiichi; Iwabuchi, Yoshiharu; Ogasawara, Kunio published the artcile< The Katsuki-Sharpless asymmetric epoxidation of (E)-2,5-dihydroxy-2,5-dimethyl-3-hexene>, Electric Literature of 617-55-0, the main research area is asym epoxidation tertiary allylic alc; Katsuki Sharpless epoxidation dihydroxydimethylhexene; absolute configuration epoxydihydroxydimethylhexane.

The first asym. epoxidation of a tertiary allylic alc. by the Katsuki-Sharpless reaction has been demonstrated using (E)-Me2C(OH)CH:CHCMe2OH as a tertiary allylic alc. substrate to afford optically active epoxide I. In 70% ee in an excellent chem. yield.

Tetrahedron Letters published new progress about Absolute configuration. 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

Graham, David E.; Graupner, Marion; Xu, Huimin; White, Robert H. published the artcile< Identification of coenzyme M biosynthetic 2-phosphosulfolactate phosphatase. A member of a new class of Mg2+-dependent acid phosphatases>, Formula: C6H10O5, the main research area is protein sequence Methanococcus gene comB ORF MJ1140 phosphosulfolactate phosphatase; coenzyme M biosynthetic enzyme phylogeny phosphoglycolate phosphatase substrate transphosphorylation.

Coenzyme M (CoM; 2-mercaptoethanesulfonic acid) is the terminal Me carrier in methanogenesis. Methanogenic archaea begin the production of this essential cofactor by sulfonating phosphoenolpyruvate to form 2-phospho-3-sulfolactate. After dephosphorylation, this precursor is oxidized, decarboxylated and then reductively thiolated to form CoM. A thermostable phosphosulfolactate phosphohydrolase (EC 3.1.3.-) catalyzing the second step in CoM biosynthesis, was identified in the hyperthermophilic euryarchaeon Methanococcus jannaschii. The predicted ORF MJ1140 in the genome of M. jannaschii encodes ComB, a Mg2+-dependent acid phosphatase that is specific for 2-hydroxycarboxylic acid phosphatase esters. Recombinantly expressed purified ComB efficiently hydrolyzes rac-2-phosphosulfolactate, (S)-2-phospholactate, phosphoglycolate and both enantiomers of 2-phosphomalate. In contrast to previously studied phosphoglycolate phosphatases, ComB has a low pH optimum for activity, a narrow substrate specificity and an amino acid sequence dissimilar to any biochem. characterized protein. Like other phosphatases that function via covalent phosphoenzyme intermediates, ComB can catalyze a transphosphorylation reaction. Homologs of comB are identified in all available cyanobacterial genome sequences and in genomes from phylogenetically diverse bacteria and archaea; most of these organisms lack homologs of other CoM biosynthetic genes. The broad and disparate distribution of comB homologs suggests that the gene has been recruited frequently into new metabolic pathways.

European Journal of Biochemistry published new progress about Divalent cations. 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

Gravatt, Christopher S.; Melecio-Zambrano, Luis; Yoon, Tehshik P. published the artcile< Olefin-Supported Cationic Copper Catalysts for Photochemical Synthesis of Structurally Complex Cyclobutanes>, SDS of cas: 151259-38-0, the main research area is alkene aliphatic copper photochem Salomon Kochi reaction catalyst; cyclobutane stereoselective preparation; alkene ligands; copper; cycloaddition; photocatalysis; small-ring compounds.

The sole method available for the photocycloaddition of unconjugated aliphatic alkenes is the Cu-catalyzed Salomon-Kochi reaction. The [Cu(OTf)]2·benzene catalyst that has been standard in this reaction for many decades, however, is air-sensitive, prone to photodecomposition, and poorly reactive towards sterically bulky alkene substrates. Using bench-stable precursors, an improved catalyst system with superior reactivity and photostability has been designed, and it offers significantly expanded substrate scope. The utility of this new catalyst for the preparation of sterically crowded cyclobutane structures is highlighted through the preparation of the cores of the natural products sulcatine G and perforatol.

Angewandte Chemie, International Edition published new progress about Alkenes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 151259-38-0 belongs to class esters-buliding-blocks, and the molecular formula is C11H19NO2, SDS of cas: 151259-38-0.

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

Booth, Paul M.; Fox, Christina M. J.; Ley, Steven V. published the artcile< Preparation of acyltetronic acids using tert-butyl acetothioacetate: total synthesis of the fungal metabolites carolic, carlosic, and carlic acids>, Application In Synthesis of 617-55-0, the main research area is carolate total synthesis; carlosate total synthesis; carlate total synthesis; acetothioacetate dianion alkylation; oxoalkanethioate preparation transesterification; oxoacyloxylalkanoate preparation ring closure.

Dianions of MeCOCH2C(O)SCMe3 were allylated with a variety of electrophiles at the γ-C. Treatment of the products with 2-hydroxy esters in the presence of Ag (I) salts gave transesterified acetoacetate derivs in good yields. These acetoacetates were cyclized to acyltetronic acid derivs using Bu4NF in THF at room temperature Natural products carlosic (I) carolic (II; R = Me) and carlic acids (II; R = CH2CO2H) acids were prepared this way.

Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) published new progress about Cyclization. 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

Falck, J. R.; Sun, Lumin; Lee, Sang Gyeong; Heckmann, Bertrand; Mioskowski, Charles; Karara, Armando; Capdevila, Jorge published the artcile< Enantiospecific synthesis of 17- and 18-hydroxyeicosatetraenoic acids, cytochrome P450 arachidonate metabolites>, Synthetic Route of 617-55-0, the main research area is hydroxyeicosatetraenoate stereoselective preparation; eicosatetraenoate hydroxy stereoselective preparation; cuprate addition bromobutanediol tosylate.

The title bioactive eicosanoids were prepared from di-Me L-malate by a convergent strategy exploiting the differential reactivity of ethereal dialkylcuprates towards tosylate vs. bromide in the intermediate I.

Tetrahedron Letters published new progress about Addition reaction, regioselective. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Synthetic Route of 617-55-0.

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

Sawano, Takahiro; Ogihara, Kei; Sagawa, Jun; Ono, Masaki; Takeuchi, Ryo published the artcile< Iridium-Catalyzed Hydroalkylation of Aliphatic Alkenes with β-Ketoesters: Formal Hydroalkylation with Methyl Ketones>, Application of C11H12O3, the main research area is iridium catalyzed hydroalkylation alkene beta ketoester; ketone preparation one pot dealkoxycarbonylation hydroalkylated intermediate.

Transition-metal-catalyzed hydroalkylation of alkenes with 1,3-dicarbonyl compounds is a useful reaction to construct a C-C bond under neutral reaction conditions in a highly atom-economical manner. We found that hydroalkylation of aliphatic alkenes with β-ketoesters proceeded with the use of a cationic iridium complex and bidentate phosphine ligand to give selectively branched α-substituted β-ketoesters in high yields. The obtained hydroalkylated compounds can be converted to β-substituted ketones through one-pot Krapcho dealkoxycarbonylation.

Organic Letters published new progress about Alkenes Role: RCT (Reactant), RACT (Reactant or Reagent). 94-02-0 belongs to class esters-buliding-blocks, and the molecular formula is C11H12O3, Application of C11H12O3.

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

Wallace, David M.; Leung, Sam H.; Senge, Mathias O.; Smith, Kevin M. published the artcile< Rational tetraarylporphyrin syntheses: tetraarylporphyrins from the MacDonald route>, Name: Ethyl 5-formyl-1H-pyrrole-2-carboxylate, the main research area is tetraarylporphyrin; porphyrin tetraaryl; condensation MacDonald tetraarylporphyrin.

Four new synthetic routes to meso-tetraarylporphyrins using a MacDonald-type [2 + 2] condensation are described. Self-condensation of a 5-aryldipyrromethane, e.g., 5-(4-tolyl)dipyrromethane, with an aryl-substituted one-carbon bridging unit affords a mixture of tetraarylporphyrins due to acid-catalyzed redistribution reactions. The second and third methods presented here show wide applicability for the preparation of 5,10,15,20-tetraaryl-substituted porphyrins, e.g., I, with 2-fold rotational symmetry and involves self-condensation of 5-aryl-1-aryldipyrromethanecarbinols, e.g., II. Finally, the 4th approach involves a [2 + 2] approach in which one of the 2 dipyrromethanes bears both of the bridging carbons in the porphyrin products, affording a porphyrin which possesses 3 different aryl rings, with one pair of uniquely opposite identical aryl groups. The last two [2 + 2] methods are further extended to give a tetraarylporphyrin bearing four different aryl groups in a predesignated array, the structure of which is confirmed by a single-crystal X-ray study.

Journal of Organic Chemistry published new progress about Condensation reaction. 7126-50-3 belongs to class esters-buliding-blocks, and the molecular formula is C8H9NO3, Name: Ethyl 5-formyl-1H-pyrrole-2-carboxylate.

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

Khan, M. K. A.; Morgan, K. J.; Morrey, D. P. published the artcile< Carbonyl derivatives of heterocyclic compounds. III. The preparation of 3-acylpyrroles>, SDS of cas: 7126-50-3, the main research area is .

Synthetic routes to 3-acylpyrroles by methods involving ring closure, transformation of substituents, and further substitution of monosubstituted pyrroles were investigated. The condensation of H2NCHCHO with acylpyruvates appears to provide a general route to the 3-ketones. The related condensation of N-carbethoxyglycine ester and nitrile gave poor yields of 3-cyanopyrrole but attempts to obtain the 3-Ac derivative by the use of MeCOCH:CH2 showed the occurrence of an alternative reaction path and gave no useful product. Attempts to convert 3-cyano- and 3-carboxypyrroles into acyl derivatives by the action of nucleophilic reagents were not successful. Pyrrole-3-carboxaldehyde was obtained by decarboxylation of the minor formylation product of Et pyrrole-2-carboxylate. 24 references.

Tetrahedron published new progress about Carbonyl compounds (organic). 7126-50-3 belongs to class esters-buliding-blocks, and the molecular formula is C8H9NO3, SDS of cas: 7126-50-3.

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

Sheppard, George S. published the artcile< Copper(II) pivalate/oxone. An improved promoter system for aryl transfer via organo-bismuth reagents>, Formula: C6H10O5, the main research area is aromatic ether preparation; alc arylbismuth arylation copper pivalate catalyst.

Effective conditions for the arylation of OH groups prone to elimination are reported. Modest success was achieved using triarylbismuth reagents under literature conditions. Based on the side-products observed in the reaction, the oxidant used for in-situ oxidation of Bi(III) to Bi(V) and the Cu salt used as promoter were modified. These changes led to substantially improved results.

Synlett published new progress about Aromatic ethers 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

Falck, J. R.; Sun, Lumin; Lee, Sang Gyeong; Heckmann, Bertrand; Mioskowski, Charles; Karara, Armando; Capdevila, Jorge published the artcile< Enantiospecific synthesis of 17- and 18-hydroxyeicosatetraenoic acids, cytochrome P450 arachidonate metabolites>, Synthetic Route of 617-55-0, the main research area is hydroxyeicosatetraenoate stereoselective preparation; eicosatetraenoate hydroxy stereoselective preparation; cuprate addition bromobutanediol tosylate.

The title bioactive eicosanoids were prepared from di-Me L-malate by a convergent strategy exploiting the differential reactivity of ethereal dialkylcuprates towards tosylate vs. bromide in the intermediate I.

Tetrahedron Letters published new progress about Addition reaction, regioselective. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Synthetic Route of 617-55-0.

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