Asymmetric synthesis of (S)-4-(2,2,4-trimethyl-1,3-dioxolan-4-yl)-1-butanol, a key intermediate for (1S,5R)-(−)-frontalin via asymmetric bromolactonization

A asymmetric synthesis of ( S )-4-(2,2,4-trimethyl-1,3-dioxolan-4-yl)-1-butanol, a key intermediate for (1 S ,5 R )-(−)-frontalin, via asymmetric bromolactonization employing ( S )-(−)-proline as a chiral auxiliary is described.