Structure of spiro[3,4-dihydro-2H-1,5-dioxadinaphtho[2,1-f:1,2-h]cyclononene-3,1'-cyclopropane

Abstract

C27H2402, M r -~- 380.5, tetragonal, crystal faces: { 101 }, { 101 }, ~ 100/, space group P4L(P43), a = 11.243 (5), c = 16.346 (6) A, V = 2066 A 3, Z = 4, D x = 1.184 Mg m -a, g(Cu Ktt) = 0.515 mm -1. The structure was solved by direct methods and refined by full-matrix least squares to a final R value of 0.054 for 1328 reflections. The molecule is asymmetric. There is little influence of strain in the small ring on the conformation of the nine-membered ring when com- pared with the cyclopropane counterpart. lntroduet|on. The structure of spiro(3,4-dihydro- 2H- 1,5-dioxadinaphtho(2,1 -f: 1,2- h)cyclononene-3, l'- cyclopentane) (I) (SNPE) was investigated in order to compare it with that of spiro(3,4-dihydro-2H-1,5- dioxadinaphtho(2, I-f: 1,2-h)cyclononene-3,1 '-cyclo- propane) (SNPR) (Stadnicka, 1979) and to find any effect of the strain in the small ring on the con- formation of the dioxacyclononene ring. The effects of the conjugated systems can be analysed by compari- son of the SNPE and SNPR structures with the struc- ture of spiro(3,4-dihydro-2H-1,5-dioxadibenzo(f,h)- cyclononene-3,1'-cyclopropane) (SBPR) (Grochowski & Karle, 1978).