Formal Total Syntheses of (+)- and (-)-Aspidophytine from a Common, Homochiral Precursor.

A formal total synthesis of (-)-aspidophytine ( 2 ), a key substructure associated with the heterodimeric indole alkaloid haplophytine ( 1 ) and itself a natural product, has been established by employing the homochiral and enzymatically derived cis -1,2-dihydrocatechol 8 as a starting material. Specifically, compound 8 has been converted into the pentacyclic product 26 , an advanced intermediate associated with a previously reported synthesis of aspidophytine ( 2 ). Simple modifications to the reaction sequence have also allowed for the identification of a synthetic pathway leading from dihydrocatechol 8 to (+)-aspidophytine ( ent - 2 ).