Acta Crystallographica Section C

Crystal Structure Communications

Volume 58, Part 5 (May 2002)

Acta Cryst. (2002). C58, o301-o304 [doi:10.1107/S0108270102005140]

Three isomeric bis(methoxycarbonyl)[2.2]paracyclophanes

P. G. Jones, J. Hillmer and H. Hopf

Abstract: The title isomers 4,16- (pseudo-ortho), 4,15- (pseudo-gem) and 4,12-bis(methoxycarbonyl)[2.2]paracyclophane (pseudo-para), C₂₀H₂₀O₄, all show the typical structural features of [2.2]paracyclophanes (flattened boat conformation of the rings, lengthened single bonds in the bridges and narrow ring angles at the bridgehead atoms). The 4,12-isomer displays crystallographic inversion symmetry. The carbonyl groups adopt a conformation in which they are directed away from the ring systems towards the nearest bridge; the corresponding angle at the ring substituent atom is widened. Crystal packing involves C-H [bold pi] interactions for the 4,15-isomer and weak C-HO hydrogen bonds for the other two isomers.

Formula: Three isomers of C₂₀H₂₀O₄

Online 30 April 2002


	Structure factor file (CIF format) (135.9 kbytes) Contains datablock IVa

	Structure factor file (CIF format) (95.4 kbytes) Contains datablock IVb

	Structure factor file (CIF format) (88.1 kbytes) Contains datablock IVd

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