Mass Spectra of Steroids

Friedland, Stephen S.; Lane, George H.; Longman, R. T.; Train, K. E.; O'Neal, M. J.

doi:10.1021/ac60146a002

Cited by 86 publications

(21 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is indicative of a ketone in conjugation with a cyclopropalle ring (20)(21)(22) lLIass spectrometry is also in accord with this structural assignment (24,25). In particular, process R/I places the double bond in the environment of ring A.…”

Section: R=h Vlllsupporting

confidence: 63%

STEROIDS: V. THE SYNTHESIS OF 4,4-Dimethyl-3α,5-Cyclocholestan-6-One (XI)

Just¹,

Richardson²

1964

Can. J. Chem.

View full text Add to dashboard Cite

The synthesis of the title compound is described.By analogy with cholesteryl derivatives, one of the expected products of the solvolysis of 4,4-dimethyl-cholesteryl tosylate should be 4,4-dimethyl-3cr,5-cyclocholestan-6~-ol (IIa) (1). Since the nature of this compound is disputed (2-4), we were interested in synthesizing it in an unambiguous fashion. This paper describes the synthesis of its immediate precursor, 4,4-dimethyl-3a,5-cyclocholestan-6-one (XI). FLOWSHEET IThe parent compound, 3a,5-cyclocholestan-6-one (11) ( 5 ) had been synthesized by Windaus by the action of potassium hydroxide on 3P-chlorocholestan-6-one (I). Our first objective therefore was the preparation of a 4,4-dimethylsteroid bearing a carbonyl function a t Ca. Nitration (6) and other methods (7-11) for introducing functional groups a t the 6 position of the readily available 4,4-dimethylcholesteryl acetate (111) (12) did not result in the formation of the desired product. However, cis-hydroxylation with osmium tetroxide gave 4,4-dimethylcholestane-3P,5a,Ga-triol acetate (IVa) in good yield. The stereochemistry is assigned in conformity with the "rule of rear-attack" (13) and is corroborated by the positive Cotton-effect (14) shown by the oxidation product of the trio1 monoacetate (IVa), 3~-acetoxy-4,4-dimethyl-5a-hydroxy-cholestan-6-one (V).The 5a-hydroxy group was not removed by the action of zinc in acetic acid (15). However, treatment with calcium in liquid ammonia (16, 17), followed by alkaline hydrolysis of the reaction product, resulted in the formation of the desired 3P-hydroxy-4,4-dimethylcholestan-6-one (VII) in 40-45y0 yield. Its structure and stereochemistry follow from its

show abstract

Section: R=h Vlllsupporting

confidence: 63%

STEROIDS: V. THE SYNTHESIS OF 4,4-Dimethyl-3α,5-Cyclocholestan-6-One (XI)

Just¹,

Richardson²

1964

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…Three of them showed a loss of water molecule at m/z 396 (compound 10) and m/z 394 (compounds 7 and 14). All of these compounds demonstrated a fragment peak attributed to the removal of the side chain in addition to three carbon groups, a well-known general fragmentation process for steroids (Friedland et al 1959;Zaretskii 1976). Rupture of the C ring, leading to a fragment ion composed from ring A and B at m/z 147, was used as an indication of the presence of a double bond within ring A at C3: this fragmentation pathway permitted to rationalize the structure of compound 4.…”

Section: Identification Of Plant Markers On Reference East Asian Papersmentioning

confidence: 97%

New criteria for the characterization of traditional East Asian papers

Avataneo

Sablier

2016

Environ Sci Pollut Res

View full text Add to dashboard Cite

We report a pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) method capable of analyzing traditional East Asian papers. The method proposed is based on rapid and easy single step Py-GC/MS analysis that can be carried out with a minimum amount of matter, in the few microgram range. Three reference papers manufactured from kozo (Broussonetia kazinoki Siebold & Zucc.), mitsumata (Edgeworthia chrysantha Lindl.), and gampi (Wikstroemia sikokiana Franch. & Sav.) with the traditional hand paper making processes were examined. The method allows discrimination between terpenic and steroid compounds, which were revealed as chemical markers of origin of the plant fibers. Each paper investigated was found to have characteristic pyrolysis fingerprints that were unique to the traditional handmade paper, demonstrating the potential for differentiation of these biochemical components of fiber plants on East Asian papers towards identification and conservation of cultural heritage. The investigation on Py-GC/MS was extended to liquid extraction followed by GC/MS analysis to characterize the biochemical components of fiber plants. The main contribution of this study is to provide molecular criteria for discriminating plant species used for traditional East Asian hand papermaking. Py-GC/MS complements efficiently microscope identification especially for adverse cases. A case study of archaeological Chinese paper painting artefacts was thereafter successfully investigated to address informative potential and efficiency of the criteria of identification on ancient and degraded East Asian paperworks.

show abstract

“…The infrared absorption spectrum of comp. SAc showed the gave three methyl signals (singlet, each 3H) at 9.12 (C-18), 8.97 (C-19), and 8.34 (C-23). Also, the doublets (each 1H) were observed at 4.60 (proton at C-6) and 4.85 (proton at C-22).…”

mentioning

confidence: 99%