The invention relates to a process for the synthesis of stilbene derivatives of formula (I)-(E) or (I)-(Z) in which R represents hydrogen or an OH group, by deprotection in the presence of an aluminum halide and of a tertiary amine of a compound of formula (II)-(E) or (II)-(Z) in which A represents hydrogen or an OR′1 group, and R1, R2, R3 and R′1 independently represent an alkyl or aralkyl group.