Crystal structures of 3,6-di-allyl-tetra-cyclo[6.3.0.0(4,11).0(5,9)]undeca-2,7-dione and 1,7-di-allyl-penta-cyclo-[5.4.0.0(2,6). 0(3,10).0(5,9)]undecane-8,11-dione: allyl-ated caged compounds.

ABSTRACT: The title compounds, C17H20O2 (1) and C17H18O2 (2), are allyl-ated caged compounds. In (1), the carbon atoms bearing the allyl groups are far apart [2.9417?(17)?Å], hence the expected ring-closing metathesis (RCM) protocol failed to give a ring-closing product. When these carbon atoms are connected by a C-C bond as in (2), the distance between them is much smaller [1.611?(3)?Å] and consequently the RCM process was successful. The caged carbon skeleton of (1) can be described as a fusion of four five-membered rings and one six-membered ring. All four five-membered rings exhibit envelope conformations. The structure of compound (2) consists of four five-membered rings, of which two are cyclo-penta-none rings bonded at the 2, 4 and 5 positions and linked at the 3-carbons by a methyl-ene bridge. It also consists of one four-membered and two six-membered rings. All four five-membered rings adopt envelope conformations. In the crystal of (1), mol-ecules are linked via C-H?O hydrogen bonds, forming sheets lying parallel to (010). In the crystal of (2), mol-ecules are linked via C-H?O hydrogen bonds forming chains along [100].

SUBMITTER: Kotha S 

PROVIDER: S-EPMC4257271 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature