"One-pot" substitution of the twenty hydrogen atoms in pentagonal dodecahedrane (C(20)H(20)) by OH, F, Cl, and Br atoms is explored. Electrophilic insertion of oxygen atoms with DMDO and TFMDO as oxidizing reagents ended, far off the desired C(20)(OH)(20), in complex polyol mixtures (up to C(20)H(10)(OH)(10) decols, a trace of C(20)H(OH)(19)?). Perfluorination was successful in a NaF matrix but (nearly