A theoretical study for manipulating molecular chirality by coherent excitation dynamics using a single, linearly polarized, coherent light pulse is presented based on the dynamics of a degenerate A-type three-level system. General properties for various laser pulse shapes are derived within an exactly solvable analytic model. In particular, conditions for complete enantiomeric conversion on and off single-photon resonance of the intermediate state are given. The method is demonstrated on the (transiently) chiral H2S2 molecule. (C) 2004 Elsevier B.V. All rights reserved.