CAS 29471-17-8 appears in our catalog under these names: 4prime,4primeprime(5primeprime)–Di–tert–butyldibenzo–18–crown–6, 4′,4′′(5′′)-Di-tert-butyldibenzo-18-crown-6, 98%, 98%, 4',4''(5'')-Di-tert-butyldibenzo-18-crown-6. Offered by: GLPBio, Chemat, MedChemExpress. Available pack sizes: 1g, 5g, 250mg, 10g, 100 mg, 250 mg.