SYNTHESIS AND CHEMISTRY OF SESQUIBICYCLO[2.2.2]OCTENE AND A TETRADECACYCLIC-CAGED SESQUIBICYCLO[2.2.2]OCTENE

Cationic rearrangements of functionalized spiro(norbornane-7,3'-bicycl o[2.2.2]octan-2'-ols) provide synthetic access to two novel polycarboc yclic alkenes, i.e., 5 and 10 (''sesquibicyclo[2.2.2]octene''). X-ray crystallographic analysis of 5 and 10 reveals that each alkene C=C dou ble bond is planar in the crystalline solid. MCPBA promoted epoxidatio n of 5 produced the corresponding oxirane, 11. Ring opening of the hig hly labile oxirane moiety in 11 occurred in the presence of mild Lewis acids (e.g., silica gel) or bases (e.g., NaHCO3), thereby affording t he corresponding cis-diol, 12. MCPBA promoted epoxidation of 7 afforde d the corresponding oxirane, 13. Oxirane 13 proved to be considerably less labile than 11 toward acidic and/or basic media. (C) 1998 Elsevie r Science Ltd. All rights reserved.