Bioinspired total synthesis of gymnothelignan N was accomplished in 13 steps and 6.7% overall yield. The synthesis features a syn Evans aldol reaction, an intramolecular hydrogenative dehydration reaction, and a phenol oxidative dearomatization/Friedel-Crafts reaction, which provides a new plausible biosynthetic pathway for the gymnothelignans and other symbiotic members. Meanwhile, another tetrahydrofuran-type lignan beilschmin A was also synthesized.