(+)-4,5-Bis[hydroxy(diphenyl)methyl]-2-methyl-2-phenyl-1,3-dioxolane (CAS# 109306-21-0) is a TADDOL (α,α,α',α'-tetraaryl-2,2-disubstituted 1,3-dioxolane-4,5-dimethanol) and is a chiral building block used in the perparation of optically active organotin derivatives. Via Ni catalyzation, (+)-4,5-Bis[hydroxy(diphenyl)methyl]-2-methyl-2-phenyl-1,3-dioxolane has been used in the cycloisomerization of dienes.