Convenient preparations of 4-methyl- and 4,6-dimethyl-10,11-dihydro-5H-dibenzo[a,d]cycloheptene using the t-butyl function as a positional protective group

The preparations of 4-methyl- and 4,6-dimethyl-dibenzo[a,d]cycloheptenes, involving three steps from a 2,8-di-t-butyldibenzo[a,d]cycloheptene, are described.