accessing enantiomericallypure stereopentads via a catalytic asymmetric sequential aldolreaction has been developed for the first time. The enantioselective sequential aldolreaction produces a wide range of chiral stereopentad precursors in good yields with excellent enantioselectivities. The key to success is the use of the sequential catalytic system involving a chiral phosphine oxidecatalyst and trichlorosilyl