A functionalized [9]cycloparaphenylene ([9]CPP) bearing three evenly spaced 5,8-dimethoxynaphth-1,4-diyl units and two macrocyclic [6]CPP precursors have been synthesized. The Diels-Alder reaction between (E,E)-1,4-bis(4-bromophenyl)-1,3-butadiene and 1,4-benzoquinone followed by methylation produces cis-5,8-bis(4-bromophenyl)-5,8-dihydro-1,4-dimethoxynaphthalene as the key intermediate for the construction of the hooplike structures. The nickel-mediated homocoupling reactions followed by aromatization led to the functionalized [9]CPP.

A heated purge-and-trap gas chromatography/mass spectrometry method was used to determine the cis- and trans-isomers of (4-methylcyclohexyl)methanol (4-MCHM), the reported major component of the Crude MCHM/Dowanol™ PPh glycol ether material spilled into the Elk River upriver from Charleston, West Virginia, on January 9, 2014. The trans-isomer eluted first and method detection limits were 0.16-μg L(-1)trans-, 0.28-μg L(-1)cis-, and 0.4-μg L(-1) Total (total response of isomers) 4-MCHM. Estimated concentrations in the spill source material were 491-g L(-1)trans- and 277-g L(-1)cis-4-MCHM, the sum constituting 84% of the source material assuming its density equaled 4-MCHM. Elk River samples collected⩽3.2 km downriver from the spill on January 15 had low (⩽2.9 μg L(-1) Total) 4-MCHM concentrations, whereas the isomers were not detected in samples collected 2 d earlier at the same sites. Similar 4-MCHM concentrations (range 4.2-5.5 μg L(-1) Total) occurred for samples of the Ohio River at Louisville, Kentucky, on January 17, ∼630 km downriver from the spill. Total 4-MCHM concentrations in Charleston, WV, office tap water decreased from 129 μg L(-1) on January 27 to 2.2 μg L(-1) on February 3, but remained detectable in tap samples through final collection on February 25 indicating some persistence of 4-MCHM within the water distribution system. One isomer of methyl 4-methylcyclohexanecarboxylate was detected in all Ohio River and tap water samples, and both isomers were detected in the source material spilled.

Treatment of 2-(1-alkynyl)phenyl isocyanates 6 with the iminophosphorane 14 produced in situ the benzoenynyl carbodiimides 15. Thermolysis of 15 under refluxing p-xylene furnished the 6H-indolo[2,3-b][1,6]naphthyridines 5, which could be regarded as the 5-aza analogues of ellipticine alkaloids. Similarly, condensation of 6 with the iminophosphorane 20 led to the formation of the 6H-indolo[2,3-b][1,5]naphthyridines 25 as the major isomer and the 10H- indolo[2,3-b][1,7]naphthyridines 26 as the minor isomer. The indolonaphthyridines 32, 33, and 34 having a methoxyl substituent were likewise synthesized. Treatment of the diisocyanate 43 with 2 equiv of the iminophosphorane 7 furnished 45 having two indoloquinoline units incorporated in a seven-fused-ring system.

Thermolysis of the carbodiimide 9a in gamma-terpinene at 138 degrees C produced 2-(phenylamino)quinoline (11a, 49%) and the parent 6H-indolo[2,3-b]quinoline (14a, 16%). Apparently, 11a was produced via the biradical 10a followed by hydrogen-atom abstraction from gamma-terpinene. A two-step biradical pathway through 12a or a one-step intramolecular Diels-Alder reaction could furnish 13a, which then underwent tautomerization to give 14a. With the carbodiimide 9b having a trimethylsilyl substituent at the acetylenic terminus, thermolysis in refluxing p-xylene at 138 degrees C produced the 6H-indolo[2,3-b]quinoline 14b (86%) exclusively. Treatment of 14b with 6 N NaOH in refluxing ethanol then furnished 14a in 92% yield. Similarly, the 6H-indolo[2,3-b]quinolines 14c-f were obtained from thermolysis of the carbodiimides 9c-f. The use of the aza-Wittig reaction between 4-methoxyphenyl isocyanate and the iminophosphoranes 2d and 2f to produce the corresponding carbodiimides followed by thermolysis furnished the 6H-indolo[2,3-b]quinolines 16d and 16f having a methoxy substituent at the C-2 position. Thermolysis of the carbodiimides 25a and 25b produced 26a and 26b having two indoloquinoline units connected at the 11 and 11' positions with either a three-carbon or a five-carbon tether. Using 1,4-phenylene diisocyanate for the aza-Wittig reaction with 2 equiv of the iminophosphorane 2g followed by thermolysis furnished 31 (66%) having two indoloquinoline units incorporated in the seven fused rings.

IV. The Moore Cyclization of Enyne-Ketenes 216 A. Formation of o-Quinone Methides 218 B. The Spiro Structures and the Annelated Quinones 218 C. Biradicals versus Zwitterions 220 V. Conclusions 221 VI. Acknowledgements 221 VII. References and Notes 221 Kung K. Wang was born in Taiwan and received his B.S. degree from Tunghai University in 1972. After two years of compulsory military service, he joined the research group of Professor Herbert C. Brown at Purdue University and obtained his Ph.D. degree in 1979. He remained at Purdue for an additional two years before joining the faculty at West Virginia University. where he is now Professor of Chemistry. His research is in the area of designing and synthesizing multifunctional reagents substituted with combinations of boron, silicon, and tin appendages for synthetic applications.