J. Chen, W. Watson, J. Kagan
Dec 15, 1978
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0
Influential Citations
4
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Journal
Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry
Abstract
The reaction of ethyl 2-formyl-2-phenylpropionate with FSO3H yields the unique compound diethyl 4•8-dimethy•-2•3;6•7-dibenz•-9-•xabicyc••[3.3.•]n•na-2•6-diene-4•8-dicarb•xy•ate. The compound crystallizes in space group PI with a = 26.486 (10), b = 8.543 (3), c = 9.467 (8) A, a = 104.38 (5), fl = 102.45 (5), y = 90.35 (3) °, V = 2022 (2) A 3 and Z = 4. Counter techniques were used to collect 5620 independent reflections. The structure was solved by application of direct-method techniques, and the model was refined by least-squares procedures to an R factor of 0.076. The eight-membered cyclooctadiene ring exhibits a conformation intermediate between the tub and boat forms. The distortion is imposed by the 1,5epoxy bridge and the 2,6-diene moieties. The conformations of the two independent molecules are identical except for a twist of one ethoxycarbonyl group.