An organocatalytic quadruple cascade initiated by a Friedel-Crafts-type reaction is described. The (S)-diphenylprolinol trimethylsilyl ether catalyzed reaction yields highly functionalized cyclohexenecarbaldehydes bearing a 1,1-bis[4-(dialkylamino)phenyl]ethene moiety and three contiguous stereogenic centers. The reaction tolerates various functional groups and all products are obtained with ve...

Tris(trimethylsilyl)silylmagnesium bromide, (Me^SiX^SiMgBr, reacts with 2.5-diisopropylbenzaldehyde to give 2,5-diisopropylphenyl-tris(trimethylsilyl)silylmethanol (1). With sodium hydride in THF compound 1 undergoes a rearrangement through 1,3-Si,O-trimethylsilyl mi­ gration affording bis(trimethylsilyl)silyl-(2,5-diisopropylphenyl)-trimethylsiloxy-methane (4). The deprotonation of 1 with orga...

A biologically active vitamin D(3) metabolite ("peak V metabolite") more polar than 25-hydroxycholecalciferol has been isolated from chicken intestines in pure form as a mono(trimethylsilyl)ether derivative. The molecule has been identified as 1,25-dihydroxycholecalciferol by means of mass spectrometry, ultraviolet absorption spectrophotometry, and specific chemical reactions.

Allamanda violacea is an ornamental plant of the genus Allamanda belongs to family Apocynaceae. Different flower extracts of the plant have been reported to possess anti-hyperlipidemic, anti-hyperglycemic and anti-oxidant activities. Present study deals with the identification of phytochemical constituents of the petroleum ether (pet ether) and chloroform extract by GC-MS analysis, and the cons...

A profile (chromatographic pattern) of the neutral and acidic metabolites present in cerebrospinal fluid from newborns and infants was obtained by gas-liquid chromatography. The metabolites are those extracted with ethyl acetate and diethyl ether. They are converted to trimethylsilyl ether derivatives, and chromatographed on a column containing 5% silicone OV-101 (methyl) packed on Chromosorb W...

A method is presented for the resolution of urinary 17-ketosteroids (17-KS) by gasliquid chromatography (GLC) for clinical application. Hot acid hydrolysis with sulfuric acid is followed by ether extraction, 1 N NaOH wash, and NaOH pellets to serve for both purifying and drying agent. All steps take place in the same re3ction tube and are adapted for mechanical shaking. The method allows one an...

Epidemiological evidence indicates that plant antioxidants activity can treat or help to prevent the development of various diseases. One species with great potential as an antioxidant is Curcuma longa. However, different extraction techniques influence isolated chemical compounds. This study investigated composition and two rhizome extracts C. longa: hydroethanolic, obtained by exhaustion (HEC...

We describe a method for obtaining profiles of neutral and acidic substances present in human cerebrospinal fluid (CSF) by gas-liquid chromatography. Metabolites extracted with ethyl acetate and ether are converted to methyl ester, trimethylsilyl ether derivatives. With this technique, acidic metabolites of brain amines, and neutral metabolites of dopamine and norepinephrine have been identifie...

An unprecedented technique for the in situ generation of indolyl ortho-quinodimethanes from 2-methylindole-based methylenemalononitriles by amine-mediated remote C(sp(3) )-H deprotonation was developed. These intermediates were efficiently trapped by diverse enals to provide a rapid entry to 2,9-dihydro-1H-carbazole-3-carboxyaldehyde structures through a formal asymmetric [4+2] eliminative cycl...