Penta-tert-butylcorannulene

The reduction of 1,3,5,7,9-penta-tert-butylcorannulene (47) with lithium progresses in four steps, and affords a paratropic dianion and a diatropic tetraanion78. This is reminiscent of the reduction process of 43. In the final stage of the reduction, however, three distinct tetraanionic species could be detected two sandwich-type diastereomers, similar to 44, and another species assigned to a tetraanionic monomer of 47, that slowly disappears. This study showed that the peri derivatization of 43 with bulky alkyl groups has little effect on its dimerization. 

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