ENONES WITH STRAINED DOUBLE-BONDS .2. BICYCLO[4.3.1]DECANE SYSTEM

When the Michael adduct (e.g., 5) of cycloheptenone with various acetoacetic esters was heated with NaOMe in MeOH, the bicyclic bridgehead ethers 9 or 10 were formed. Several procedures (see Scheme III) have been used to convert these bridgehead ethers 9 and 10 to the enone 2 with a bridgehead carbon-carbon double bond. Although the enone 2 is a relatively reactive acceptor for the conjugate addition of nucleophiles, it is stable in the absence of nucleophiles and has shown no tendency to undergo thermally induced cyclodimerization. © 1979, American Chemical Society. All rights reserved.