Protoadamantanes by Ring Closure Reactions

In addition to the skeletal rearrangements of the adamantane nucleus described above, several ring closure reactions have also been developed for the 

9-dehydroadamantane 82) with lithium in ammonia which gives 5-proto-adamantanone (Eq. (23))40) and the pyrolysis of 7-allyloxycycloheptatriene (Eq. (24)) which results in the formation of two unsaturated protoadamanta-nones, 39 (tricyclo [4.3.1.0 3 8] dec-4-en-2-one) and 40 (tricyclo [4.3.1.0 3 8)]- 

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