Abstract
HEXACYCLO[7.4.0.02,8.03,7.06,11]tridecane-10,13-dione (“homosecohexaprismane-10,13-dione”, 8) has been prepared via a six-step sequence that results in homologation of two of the cyclopentane rings in pentacyclo[5.4.0.02,6.03,10.05,9]-undecane-8,11-dione, 1. The structure of 8 has been established unequivocally via single crystal X-ray structural analysis.