Dendrobine support studies. The structure of a novel 3-azatricyclo[6.2.1.0(4,11)]-undecane derivative

(1S*, 4R*, 8S*, 11R*)-3-Diphenylmethyl-11-methyl-3- azatricyclo[6.2.1.0(4,11)]undec-5-en-2-one, C24H25NO, Mr = 343.47, monoclinic, P2(1), a = 10.248 (3), b = 8.859 (2), c = 10.344 (2) A, beta = 99.816 (14) degrees, V = 925.4 (3) A3, Z = 2, D chi = 1.23 g cm-1 (163 K), lambda(Mo K alpha) = 0.7107 A, mu = 0.6927 cm-1, F(000) = 368, T = 163 K, R = 0.0423 for 2569 reflections. The compound is spontaneously resolved upon crystallization. The N atom appears to be sp2 hybridized [N is 0.0901 (13) A from plane through three ligand atoms] and in conjugation with the carbonyl group [short N--C bond 1.351 (2) A]. The tricyclic ring system is concave. Ring strain appears to affect C--C bond lengths of the central atom of the 3-ring system. The average C--C bond length for this atom to other ring atoms is 1.551 (2) while the average for all other sp3 C--sp3 C bonds is 1.530 (2) A.