نتایج جستجو برای: alcohols and phenols

تعداد نتایج: 16830469  

In multi-step organic syntheses, the protection and deprotection of tetrahydropyranyl (THP) ethers is one of the most frequently used methods. Over the years, different methods have been used from various catalytic systems for the protection of hydroxyl groups as THP ethers and their deprotection. Herein we have reported that various alcohols and phenols have been efficiently converted to the c...

Journal: :inorganic chemistry research 0
davud karimian isfahan university bahram yadollahi department of chemistry, university of isfahan, iran valiollah mirkhani departemnt of chemistry, univarsity of isfahan, iran

in multi-step organic syntheses, the protection and deprotection of tetrahydropyranyl (thp) ethers is one of the most frequently used methods. over the years, different methods have been used from various catalytic systems for the protection of hydroxyl groups as thp ethers and their deprotection. herein we have reported that various alcohols and phenols have been efficiently converted to the c...

Journal: :Molecules 2015
Luca Forti Simone Di Mauro Maria Rita Cramarossa Sara Filippucci Benedetta Turchetti Pietro Buzzini

The rising consumer requests for natural flavors and fragrances have generated great interest in the aroma industry to seek new methods to obtain fragrance and flavor compounds naturally. An alternative and attractive route for these compounds is based on bio-transformations. In this review, the application of biocatalysis by Non Conventional Yeasts (NCYs) whole cells for the production of flav...

Journal: :The Analyst 2001
G Diehl A Liesener U Karst

The first hyphenation of high performance liquid chromatography (HPLC), electrochemical online oxidation and mass spectrometry (MS) is described. Ferrocenecarboxylic acid esters of various alcohols and phenols have been synthesized, separated by reversed-phase HPLC and oxidized (ionized) coulometrically prior to single quadrupole MS analysis using electrospray ionization (ESI) and atmospheric p...

Journal: :Organic & biomolecular chemistry 2012
Phillip I Jolly Nadia Fleary-Roberts Steven O'Sullivan Eswararao Doni Shengze Zhou John A Murphy

The bis-pyridinylidene 13 converts aliphatic and aryl triflate esters to the corresponding alcohols and phenols respectively, using DMF as solvent, generally in excellent yields. While the deprotection of aryl triflates has been seen with other reagents and by more than one mechanism, the deprotection of alkyl triflates is a new reaction. Studies with (18)O labelled DMF indicate that the C-O bo...

Journal: :Journal of chromatographic science 1998
M J Oruña-Concha J López-Hernández J A Simal-Lozano J Simal-Gándara M J González-Castro C de la Cruz García

"Padrón-type" peppers are a small variety of Capsicum annuum cultivated mainly in Galicia, Spain. To compare the effects of freezing and freeze-drying on the volatile components of Padrón-type peppers, preserved samples are analyzed by means of dynamic headspace sampling on an adsorbent followed by microwave desorption into a gas chromatograph equipped with a mass spectrometric detector. Sixty-...

Journal: :Angewandte Chemie 2017
Bartosz Bieszczad Declan G Gilheany

A simple, general and practical method is reported for highly enantioselective construction of tertiary alcohols through the direct addition of organomagnesium reagents to ketones. Discovered by rational ligand design based on a mechanistic hypothesis, it has an unprecedented broad scope. It utilizes a new type of chiral tridentate diamine/phenol ligand that is easily removed from the reaction ...

A mild, efficient and fast method for the trimethylsilyl (TMS), tetrahydropyranyl (THP) and methoxymethyl (MOM) protection of alcohols and phenols in the presence of sulfonated rice husk ash (RHA-SO3H) is reported. All reactions were performed at room temperature in high to excellent yields. All the products are separated and compared with authentic samples and/ or identified using different ty...

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