Formation of Menthane or Cyclopropane Derivatives

Derivatives of m-menthenes and m-menthadienes were also almost exclusively produced on treatment of car-4-ene oxide664 or 5-acetylcar-2-ene oxide665 with HC1. Reaction of car-3-ene oxide with ZnBr2 gave m-menth-5-en-2-one.666 

Car-3-ene is known to be a convenient starting material for access to the irregular chrysanthemyl skeleton (see Section 14). The (+)-olefin has been again stereo-specifically converted (via hydration and oxidation) into (+)-dihydrochrysanthemo-lactone and (+)-methyl m-chrysanthemate.667 668 Other 1,2-cis-cyclopropane derivatives have resulted from oxidative cleavage of derivatives of the same substrate.669-671 

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