Decalin analysis

Polycyclic compounds are common in nature, and many valuable substances have fused-ring structures. For example, steroids, such as the male hormone testosterone, have 3 six-membered rings and 1 five-membered ring fused together. Although steroids look complicated compared with cyclohexane or decalin, the same principles that apply to the conformational analysis of simple cyclohexane lings apply equally well (and often better) to steroids. 

The photolysis vessels were equipped with a gas inlet, serum-capped opening for aliquot removal, and a water-cooled condenser. The irradiated solutions also contained decalin (1.5 x 10 3 M), which was utilized as an internal standard for gc analysis (Varian Aerograph 2400, flame ionization detector,... 

Figure 5.15. Gas chromatograms of liquid precursors for producing n-type Si films, namely, solution of CPS with white phosphorus dissolved at 1 wt% initial (nonirradiated) solution 20-min-, 25-min-, and 30-min-irradiated solutions and white phosphorus alone solution, for comparison, all of which were diluted with toluene before analysis. Trans-decalin was used as a standard for a quantitative estimation of an unreacted CPS monomer. [Reproduced with permission from Ref. 25. Copyright 2007 The Japan Society of Applied Physics.]...

ESR spectra for, 22 294, 301 as high-energy fuels, 18 2-4 hydrogenation course of, 18 6-8 equilibria, 18 7, 8 kinetic processes, 18 6, 7 experimental procedures, 18 19, 20 apparatus and methods, 18 20 materials, 18 20 mechanism of, 18 21-45 formation of isomeric decahydro-naphthalenes, 18 23-30 deuterogena-tion of - -octalin, 18 29 routes to trans isomers, 18 26-30 selectivity to trons-decalin, 18 24, 25 olefin intermediates, 18 30-45 dihydro-and hexahydronaphthalenes, 18 32, 33 analysis of products, 18 33 oc-tahydronaphthalenes, 18 34-45 analysis of products, 18 34 deu-... 

The success of the gas phase electron diffraction analysis of cis-and /ra 5-decalin (123) is another example of the use of MM calculations as an auxiliary technique. Minimum energy conformations and vibrational ampUtudes were calculated by both the Lifson and Boyd force fields (30,31) and were used as the starting values for refinement of the geometrical and vibrational parameters for the least-squares analysis. The results revealed no appreciable strain in cj5-decalin (123) other than that expected from gauche interactions. 

With this idea in mind, the retrosynthetic analysis (Scheme 13.2.8) leads now to unsaturated cw-decalin 28 which could be reduced to 5-methyl-2-cyclohexenone 31. In the synthetic direction there was initially the uncertainty of whether nitrone 27 would cyclise to 26b rather than to the desired adduct 26a (see below Scheme 13.2.9). However, the authors felt that in fact the risk was "less critical in view of the regioselectivity observed in intramolecular N-alkenylazomethinimine additions involving non-polarised olefinic bonds" [11][12]. 

Smith and Burwell [61) showed that the reaction of deuterium with j9.io-octalin, which is catalyzed by reduced platinum oxide, yields a mixture of cis- and /mws-decalins containing an average of nearly three deuterium atoms per molecule. Under the same conditions J -octalin gave somewhat less of the cis isomer but the saturated products contained an average of two deuterium atoms per molecule. From a detailed analysis of the distribution of deuterium in the products they concluded that most of the cis- and all of the frans-decalin produced from... 

The addition of organocuprates to chiral decalin enone systems has been explored in the context of steroid synthesis. For the addition of lithium dimethylcuprate to enones 28, 31, and 34, the major diastereomer obtained can easily be predicted by employment of a qualitative conformational analysis (Scheme 6.6) [11-13]. Thus,... 

The complete NMR analysis of the bicyclic decalin-like bis-l,3-oxathiane 107 revealed the t-position of 1,5-dioxa-3,7-dithiadecalin, the equatorial position of the phenyl substituents, and the axial orientation of the R substituent at the same skeletal position <20040121 >. By the same methods, the stereochemistry of the spiro analog 108 was clarified <1998C267>. 

Four model compounds, n-undecane, tetralin, cis/trans decalin and mesitylene, and a natural gas condensate from the North Sea were also cracked. Analyses and the reference code key of the coal-based feedstocks and the gas condensate are given in Table 1. Paraffin, naphthene, and aromatic-type analyses were calculated from gas chromatographic analyses of the partially hydrogenated anthracene oil and gas condensate whereas, mass spectrometric analysis was performed on the two coal extract hydrogenates and their further hydrogenated products. 

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