Formation of Diastereoisomeric Pinacols via Reductive Coupling of D(3)-Trishomocubanone

摘要

The X-ray crystal structure of spiro(pentacyclo(7.3.0.0(4,8).0(5,12).0(7,11))dodecan-2-one-3,11'-pentacyclo(6.3.0.0(2,6).0(3,10).0(5,9))undecane), C22H24), is reported. Compound (4b) consists of two spiro-fused cage systems. One cage is composed of three fused norbornane (bicyclo(2.2.1)heptane) moieties, while the other contain two norbornane and one bicyclo(2.2.2)octanone moiety. The ideal envelope conformations of the five-membered rings comprising the norbornane moieties are significantly twisted by the ring fusions with the normal 0 deg torsion angles form 16.6(2) to 28.5(2). The bicyclooctane system also exhibits large twist distortions. Keywords; Cage ketones, Ketones, Reprints. (KT)