Preparation method of benzofurocoumarin compound

The invention discloses a preparation method of a photoactive benzofurocoumarin compound. The photoactive benzofurocoumarin compound is a compound shown as a formula I; the enantioselectivity of the compound shown in the formula I is up to 95-99%. The photoactive benzofurocoumarin skeleton of the compound contains two chiral centers; the photoactive benzofurocoumarin compound containing the two chiral centers is synthesized by adopting a 1, 4-addition reaction strategy, taking common and easily available chiral alkali as a catalyst and taking 3-acyl coumarin and benzofuran imine with differentstructures as substrates. The method is low in raw material price, simple and convenient to operate, low in equipment requirement, environment-friendly, safe to operators, mild in reaction condition,high in yield, high in enantioselectivity, wide in substrate application range and relatively large in industrial potential. 本发明公开了一种光活性苯并呋喃香豆素化合物的制备方法。所述光活性苯并呋喃香豆素化合物如式Ⅰ所示化合物；式Ⅰ所示化合物的对映选择性高达95～99％。本发明光活性苯并呋喃香豆素骨架含有两个手性中心，采用1