Studies on terpenes. Part I. Rearrangement of 7-oxatricyclo[4,3,0,0]nonanes into 8-substituted 1,3,3-trimethylnorbornane derivatives

Abstract

9-Methyl-6-p-tolyl-(III; R = C₆H₄Me-p) and 6,9-dimethyl-7-oxatricyclo[4,3,0,0]nonane (III; R = Me) are readily rearranged into 8-substituted 1,3,3-trimethylnorbornan-2α-ols by treatment with boron trifluoride–ether. 9-Methyl-7-oxatricyclo[4,3,0,0]nonane (III; R = H) is rearranged (BF₃–OEt₂) to a mixture of endo-3α-acetoxymethyl-3-methylnorbornan-2α-yl acetate (VIII; R = Ac) and exo-7-acetoxymethyl-7-methylnorbornan-2β-yl acetate (IX; R = Ac).