28801-55-0 29471-17-8 50855-11-3 88155-39-9 Dibenzo(b,k)(1,4,7,10,13,16)hexaoxacyclooctadecin, 2,13(or 2,14)-bis(1,1-dimethylethyl)-6,7,9,10,17,18,20,21-octahydro- Dibenzo(b,k)(1,4,7,10,13,16)hexaoxacyclooctadecin, 6,7,9,10,17,18,20,21-octahydro-2,13(or 2,14)-bis(1,1-dimethylethyl)-