Method for synthesizing chiral tetrahydrobenzoxepine compound through asymmetric cycloaddition reaction catalyzed by gold

The invention provides a method for synthesizing a chiral tetrahydrobenzoxepine compound through asymmetric cycloaddition reaction catalyzed by gold, which comprises the following steps: in a solvent A, under the catalysis of a gold catalysis system, performing asymmetric [3 + 4] cycloaddition reaction on an alkyne ketene compound I and an o-methylene benzoquinone compound II to obtain the chiral tetrahydrobenzoxepine compound. A chiral tetrahydrobenzoxazepine compound III is obtained; the gold catalysis system is composed of a gold catalyst, a chiral ligand and a silver salt, and the chiral ligand has a structure as shown in a formula IV. The tetrahydrobenzoxepine compound is constructed through the asymmetric cycloaddition reaction catalyzed by gold, and the method has the advantages that the operation is convenient and simple, the yield is high, the reaction raw materials are low in price and easy to obtain, the catalyst cost is low, the substrate application range is wide, the diastereoselectivity is good