[aR,(-)]-1,1'-Binaphthalene

Purify 1,1’-binaphthyl through a silica gel column with Me2CO/*C6H6 [or Al2O3 with 10% *C6H6/pet ether (b 30-60o)] and recrystallise it from EtOH, pentane, or slow evaporation of *C6H6, Me2CO or Et2O solutions. Half life ~10hours at 25o in various solvents. [Wilson & Pincock J Am Chem Soc 97 1474 1975, Akimoto & Yamada Tetrahedron 27 5999 1971, Beilstein 5 I 358, 5 II 642, 5 III 2465, 5 IV 2634.]