نتایج جستجو برای: activated acetylenic compounds
تعداد نتایج: 441223 فیلتر نتایج به سال:
A new benzofuran glycoside, masutakeside I (1) and a new C10 acetylenic acid, masutakic acid A (2) were isolated from the fruiting bodies of the fungus Laetiporus sulphureus var. miniatus. Their structures were established by spectroscopic and chemical methods. The known compounds 3-6 were also obtained and identified as egonol, demethoxyegonol, egonol glucoside and egonol gentiobioside. Some o...
Two pairs of diastereoisomeric acetylenic norlignan compounds with PhCH(OR(1))CH(OR(2))CH(2)C triple bond CPh skeleta: (1R, 2R)-1-O-methylnyasicoside (1) and (1S, 2R)-1-O-methylnyasicoside (2), and (1R, 2R)-crassifogenin D (3) and (1S, 2R)- crassifogenin D (4), were isolated from the ethanolic extract of rhizomes of Curculigo crassifolia. Compounds 3 and 4 are new and their structures were eluc...
Substituted pyrroles were prepared by a gold(I)-catalyzed acetylenic Schmidt reaction of homopropargyl azides. The reaction allows for regiospecific substitution at each position of the pyrrole ring under mild conditions. A mechanism in which azides serve as nucleophiles toward gold(I)-activated alkynes with subsequent gold(I)-aided expulsion of dinitrogen is proposed.
Abstract Terminal propargylic compounds containing an alkyne unit and an alcohol or ester group in the propargylic position have a fairly acidic acetylenic hydrogen atom; this makes them versatile substrates for further chemical transformation. Some transition metals such as ruthenium or copper exhibit specific affinity for terminal propargylic compounds, generating dielectrophilic ruthenium– o...
Two new acetylenic fatty acids (1, 2), a new triglyceride (3), along with eleven known compounds including 3-oxo-11alpha,12alpha-epoxyurs-13beta,28-olide (4) previously reported as a synthetic compound, have been isolated from the leaves of Hymenodictyon excelsum. The structural identification was established from spectroscopic data.
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید