Total synthesis of (.+-.)-N-(phenylsulfonyl)- and (.+-.)-N-(tert-butyloxycarbonyl)-CI, (.+-.)-CI-CDPI1, and (.+-.)-CI-CDPI2: CC-1065 functional analogs incorporating the parent 1,2,7,7a-tetrahydrocycloprop[1,2-c]indol-4-one (CI) left-hand subunit