Towards the total synthesis of cyclo[n]carbons and the generation of cyclocarbon
We describe efforts towards the synthesis of some allotropes of carbon, the cyclo[n]carbons where n= 18, 24 and 30. The key intermediate 11 is hexa-1,3,5-triyne with the central triple bond masked as a 1-amino-1,2,3-triazole derivative. Cyclo-oligomerisation of this by oxidative coupling gives macrocylic precursors of C18, C24, and C30. C30 is a proposed intermediate in the formation of C60 and we also describe some attempts at the synthesis of C60via the chemical generation of benzotryne, cyclocarbon.