Abstract: A preferred embodiment of the present invention comprises method for planning the synthesis of one or more chemical compounds with specified chemical properties, comprising the steps of: (a) representing a space of synthesis plans, wherein each synthesis plan in the space of synthesis plans represents one or more vitual reaction schemas applied to one or more classes of virtual input reactants; (b) representing a space of virtual compounds, wherein each compound in the space of virtual compounds is a product of one or more of said synthesis plans; (c) constructing a first mapping from the space of virtual compounds to range space representing the desirability of a compound, wherein the first mapping is determined by one or more compound properties being measured; and (d) searching the space of synthesis plans for desirable compounds as represented in the range space.