Acid-Catalyzed Cyclization of 3,3',4,4'-Tetrahydro-1,1'-binaphthyl and Single-Crystal X-ray Structure Determination of a Polycyclic Stable Ozonide

Article abstract of DOI:10.1021/jo00180a014

Amberlyst-15 (A-15) catalyzed cyclization of 3,3',4,4'-tetrahydro-1,1'-binaphthyl (1) in refluxing toluene during 12h provided , as the major product , (+/-)-1,2,3,6b,7,8-hexahydrobenzofluoranthene (2a).Ozonization of 2a gave a stable ozonide (3), mp 159-161 deg C.The structure of this ozonide was established by single-crystal X-ray analysis: monoclinic unit cell P2₁/c, a= 10.616(1) Angstoem, b= 9.607(3) Angstroem, c= 15.052(4) Angstroem, β= 105.06(2) deg, D_calcd 1.372 g cm^-1, Z= 4, final agreement factor 6.3percent.Prolonged treatment (12-100 h) of 1 or 2a with A-15 in refluxing toluene yielded a mixture of three1,2,3,6b,7,8,12b,12c-octahydrobenzofluoranthenes ( 4a, 4b, 4c) and 1,2,3,12c-tetrahydrobenzofluoranthene (5).Hydrocarbon 2a was readily dehydrogenated in the presence of hot Pd/C to benzofluoranthene (6).