(1β,5β)-8β-(1-Hydroxy-1-methyl-2-propenyl)-6,6-dimethyl-bicyclo[3.3.0]octan-2-one ethylene acetal C??? ??, ??, ??

(1β,5β)-8β-(1-Hydroxy-1-methyl-2-propenyl)-6,6-dimethyl-bicyclo[3.3.0]octan-2-one ethylene acetal ?? ?? ? ???

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(1β,5β)-8β-(1-Hydroxy-1-methyl-2-propenyl)-6,6-dimethyl-bicyclo[3.3.0]octan-2-one ethylene acetal ?? ??