Ethanoadamantane. Most stable C12H18 isomer

Fǎrcaşiu, D.; Wiskott, E.; Ōsawa, Eiji; Thielecke, Wilfried; Engler, E. M.; Slutsky, Joel; Schleyer, Paul von Ragué; Kent, Gerald J.

doi:10.1021/ja00821a051

Cited by 25 publications

(20 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most stable C 12 H 18 hydrocarbon is ethanoadamantane 10 (Figure ). This hydrocarbon has the correct symmetry but the reported 13 C NMR spectrum was different from that of our unknown molecule . In order to evaluate how many structures are possible, we used the program MOLGEN 5.0 to generate all possible structures containing six CH and six CH 2 groups, with the only constraint being that no rings smaller than 5-membered ones are present.…”

Section: Results and Discussionmentioning

confidence: 71%

Technical Synthesis of 1,5,9-Cyclododecatriene Revisited: Surprising Byproducts from a Venerable Industrial Process

et al. 2019

View full text Add to dashboard Cite

The synthesis of 1,5,9-cyclododecatriene by selective trimerization of butadiene catalyzed by TiCl4 and ethylaluminum sesquichloride has been commercially used since 1965. Although thoroughly investigated, not all details of the mechanism are completely understood. The recent development of a new process to produce cyclododecanone involving oxidation of 1,5,9-cyclododecatriene with N2O has led to the serendipitous discovery of an array of hitherto unknown byproducts, formed in the trimerization of butadiene: eleven tricyclic C12H20 and one tetracyclic C12H18 hydrocarbons, three of which had never been described before. The identification of these byproducts became possible by using a combination of chemical enrichment, high-resolution distillation, 13C-2D-INADEQUATE NMR, and comparison with ab initio calculated spectra, thus demonstrating the power of these combined techniques. The identification of these byproducts contributes to a better understanding of the mechanism of this centrally important reaction.

show abstract

Section: Results and Discussionmentioning

confidence: 71%

Technical Synthesis of 1,5,9-Cyclododecatriene Revisited: Surprising Byproducts from a Venerable Industrial Process

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Recall the hydrocarbons isowurtzitane and wurtzitane (more often called iceane). Both of these species are less stable than their isomer ethanoadamantane [93]. What does that suggest about the nitro and/or aza derivatives of isowurtzitane, wurtzitane, and ethanoadamantane?…”

Section: Issuementioning

confidence: 99%

Interplay of thermochemistry and structural chemistry, the journal (volume 24, 2013, issues 5–6) and the discipline

2014

View full text Add to dashboard Cite

show abstract

“…1, Fig. S1) is reported to be 6-7 kcal/mole more stable than iceane which also possesses unfavourable entropy resulting from its high symmetry (Farcasiu et al, 1974). Of all the possible tetracyclic caged hydrocarbons, the most stable ethanoadamantanes and iceanes are most likely to persist during the cracking process (Osawa et al, 1980).…”

Section: Introductionmentioning

confidence: 99%

“…Iceane was synthesised in the 1970s (Hamon and Taylor, 1975;Hamon and Taylor, 1976) and its crystal structure determined by X-ray diffraction (Hamon et al, 1977). However, iceane is not the most stable isomer due to the strain energy of ca 25 kcal/mole resulting from the three flagpole-flagpole interactions (Farcasiu et al, 1974). The less symmetrical non-diamondoid structure tetracyclo[6.3.1.0 2,6 .0 5,10 ]dodecane (2,4-ethanoadamantane; Fig.…”

Section: Introductionmentioning

confidence: 99%

“…Li et al, 2012;Silva et al, 2013;Silva et al, 2011;Tran et al, 2010). As neither iceane nor 2,4ethanoadamantane were readily available commercially, the latter was synthesised using a synthetic protocol previously reported in the literature (Farcasiu et al, 1974;Osawa et al, 1980). Following tentative assignment of peaks present in the alkyldiamantane mixture, their two dimensional (2D) retention times and time of flight mass spectra were used to investigate 29 Australian crude oils and condensates.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Comparison of tri-, tetra- and pentacyclic caged hydrocarbons in Australian crude oils and condensates

Scarlett

Spaak

Mohamed

et al. 2019

Organic Geochemistry

View full text Add to dashboard Cite

Thermally stable and biodegradation resistant, the tricyclic and pentacyclic diamondoid caged hydrocarbons are commonly used as source and maturity indicators of oils and potential source-rocks but similar tetracyclic structures appear to have received much less attention. Using two-dimensional gas chromatography-time of flight mass spectrometry (GC×GC-TOFMS), 29 Australian crude oils and condensates were analysed for the presence of caged C12H18 tetracyclics such as ethanoadamantane and iceane. The thermodynamically more stable 2,4-ethanoadamantane was identified by comparison with a synthesised authentic standard. Three of its bridgehead methylsubstituted isomers, 6-methylethanoadamantane (6-ME), 1-ME and 2-ME, were tentatively assigned based on mass spectral comparison and relative elution order. Further series of non-bridgehead methyl isomers plus dimethyl isomers were also inferred based on mass spectra and 2D elution positions. The tri-, tetra and pentacyclic caged hydrocarbons and their methyl-substituted homologues were semi-quantified in the Australian oils. The potential of a novel index, the methylethanoadamantane index (MEI), based on the ratio of the more stable bridgehead isomers divided by the sum of all the methyl substituted isomers (MEI = Σ(6-ME + 1-ME + 2-ME)/ΣTotal methylethanoadamantanes), was explored. A significant positive association was found between the MEI and MAI (r 2 = 0.203, p<0.05) and a significant negative association was found between MEI and MDI (r 2 = 0.246 p <0.05). Stronger relationships were found for other commonly applied diamondoid ratio indices including Σ Methyl Adamantanes/Σ Methyl Diamantanes (ΣMA/ΣMD) versus ΣMA/ΣME (r 2 = 0.781, p<0.0001, n=26). The relatively low volatility of the ethanoadamantanes compared to the adamantanes and their likely greater resistance to microbial attack than the ethyladamantanes may make analysis of these compounds a useful addition to the commonly measured diamondoids.

show abstract

Ethanoadamantane. Most stable C12H18 isomer

Cited by 25 publications

References 4 publications

Technical Synthesis of 1,5,9-Cyclododecatriene Revisited: Surprising Byproducts from a Venerable Industrial Process

Technical Synthesis of 1,5,9-Cyclododecatriene Revisited: Surprising Byproducts from a Venerable Industrial Process

Interplay of thermochemistry and structural chemistry, the journal (volume 24, 2013, issues 5–6) and the discipline

Comparison of tri-, tetra- and pentacyclic caged hydrocarbons in Australian crude oils and condensates

Contact Info

Product

Resources

About