Construction of a quaternary carbon center via cyclic sulfite

Reaction of (S)-2-oxo-4-methyl-4-phenyl-1,3,2-dioxathiolane with triethylaluminum selectively took place at the tertiary carbinol center to give (R)-2-methyl-2-phenyl-1-butanol. Enhanced stereoselectivity was obtained in a nonpolar solvent. Similarly, a series of (S)-4,4-disubstituted-1,3,2-dioxathiolanes reacted with trimethylaluminum to afford the corresponding (R)-2-alkyl-2-phenyl-1-propanols in good yields.