The major molecular species of amniotic fluid phosphatidylcholine were determined as diacylglycerol trimethylsilyl ether derivatives by gas-liquid chromatography with use of glass capillary columns. We studied amniotic fluid specimens from 48 pregnancies. As expected, the major disaturated species of amniotic fluid phosphatidylcholine, dipalmitoylphosphatidylcholine, and palmitoylmyristoylphosp...

A simple method is described for the determination of molecular species of enantiomeric sn-1,2- and sn-2,3-diacylglycerols derived from natural triacylglycerols by Grignard degradation. The method is based on a preparative separation of the enantiomeric diacylglycerols as 3,5-dinitrophenylurethane (DNPU) derivatives by high performance liquid chromatography (HPLC) on a chiral column (25 cm x 4....

Mycocerosic acids of Mycobacterium tuberculosis were studied by gas chromatography–mass spectrometry. Mycobacterial cells were subjected to alkaline hydrolysis and then acidified before being extracted using petroleum ether to collect the acids. Methyl ester, trimethylsilyl and pentafluorobenzyl derivatives of the mycocerosic acids were formed. In the electron impact mode, using selected-ion mo...

α-Hydroxyalkylidene carbenes, generated from thermolysis of α,β-epoxy-N-aziridinylimines, undergo diastereotopic group selective 1,5 C–H insertion reactions on 2,4-dimethyl-8-oxabicyclo[3.2.1]oct-6-ene ring systems. Protection of a tertiary alcohol at C-3 of the bridged oxabicycle as a trimethylsilyl ether reverses the sense of diastereoselectivity. 1,5 C–H insertion into a methine adjacent to ...

The direct synthesis of 1,1?,2,2?-tetralithioferrocene from 1,1?,2,2?-tetrabromoferrocene is reported. In addition, the related 1,1?,2,2?,3,3?-hexalithioferrocene also described, prepared directly 1,1?,2,2?,3,3?-hexabromoferrocene. These lithioferrocenes may be isolated as orange red (tetralithio) and (hexalithio) powders, respectively. When these are in situ reacted with chlorotrimethylsilane,...

Starting from tris(trimethylsilyl)silane the novel 2-chloro-3,4-bis-tris(trimethylsilyl)silyl-cyclo-diphospha-diazenium-tetrachloridogallate salt (7) was prepared in a six step synthetic procedure including the synthesis of N-tris(trimethylsilyl)silyl-aminodichlorophosphine (4) and 1,3-dichloro-2,4-bis-tris(trimethylsilyl)silyl-cyclo-diphospha-diazane (5). All intermediate products along the re...

Difluorocarbene, generated from trimethylsilyl fluorosulfonyldifluoroacetate (TFDA), reacts with the uridine and adenosine substrates preferentially at the enolizable amide moiety of the uracil ring and the 6-amino group of the purine ring. 2',3'-Di-O-acetyl-3'-deoxy-3'-methyleneuridine reacts with TFDA to produce 4-O-difluoromethyl product derived from an insertion of difluorocarbene into the ...

Geminal dimetalated amines, phosphanes, and arsanes gained increasing attention due to the expectation of a high reactivity and unique solid-state structures. Power et al.1 reported the molecular structure of a hexameric ether complex of a magnesium imide. The aryl substituent at the nitrogen atom has been a phenyl1 or a naphthyl group.2 Furthermore, the high reactivity allows the synthesis of ...