نتایج جستجو برای: activated acetylenic compounds

تعداد نتایج: 441223  

Journal: :Chemical & pharmaceutical bulletin 2001
K Yoshikawa S Bando S Arihara E Matsumura S Katayama

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...

Journal: :Molecules 2008
Kai-jin Wang Ning Li Hu Wang

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...

Journal: :Journal of the American Chemical Society 2005
David J Gorin Nicole R Davis F Dean Toste

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.

2015
Xin-Hu Hu Zhen-Ting Liu Long Shao Xiang-Ping Hu

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...

Journal: :Chemical & pharmaceutical bulletin 2009
Parichat Nareeboon Wichan Komkhunthot Decha Lekcharoen Nuanchawee Wetprasit Chudaporn Piriyapolsart Somyote Sutthivaiyakit

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.

Journal: :Journal of Synthetic Organic Chemistry, Japan 1963

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