نتایج جستجو برای: alcohols and phenols
تعداد نتایج: 16830469 فیلتر نتایج به سال:
Ruthenium(III) chloride-catalyzed acylation of a variety of alcohols, phenols, and thiols was achieved in high yields under mild conditions (room temperature) in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF(6)]). The ionic liquid and ruthenium catalyst can be recycled at least 10 times. Our system not only solves the basic problem of ruthenium catalyst reuse, but ...
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...
A wine’s aroma profile is an important part of the criteria affecting wine acceptability by consumers. Its characterisation complex because volatile molecules usually belong to different classes such as alcohols, esters, aldehydes, acids, terpenes, phenols and lactones with a wide range polarity, concentrations undesirable off-aromas. This review focused on mechanisms conditions formation indiv...
Selective acylation of alcohol has enjoyed great attraction of chemists due to its significance in synthetic organic chemistry especially in protecting group chemistry as reflected by the number of methods that have been developed to effect this transformation. To meet the challenging task of chemoselective transformation of aliphatic alcohols in the presence of phenolic alcohol mainly acidic c...
To investigate the phenolic and aroma composition of Malvazija istarska (Vitis vinifera L.) white wines produced by an unconventional technology comprising prolonged maceration followed by maturation in wooden barrels, representative samples were subjected to analysis by UV/Vis spectrometry, high-performance liquid chromatography, and gas chromatography-mass spectrometry. When compared to stand...
The catalytic, enantioselective, cyclization of phenols with electrophilic sulfenophthalimides onto isolated or conjugated alkenes affords 2,3-disubstituted benzopyrans and benzoxepins. The reaction is catalyzed by a BINAM-based phosphoramide Lewis base catalyst which assists in the highly enantioselective formation of a thiiranium ion intermediate. The influence of nucleophile electron density...
Volatile compounds from smoked dry-cured ham were isolated by using headspace-solid phase microextraction and gas chromatography-mass spectrometry (GC-MS). Samples of biceps femoris were also evaluated for sensory physical and chemical characteristics. Eighty seven volatile aroma compounds of smoked dry-cured ham were identified. Chemical groups identified were aldehydes (35.6%), phenols (34.3%...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید