Abstract Five new α-pyrone derivatives, necpyrones A–E (1–5), together with seven known compounds (6–12), were isolated from the extract of an endolichenic fungus Nectria sp. Chemical structures of these compounds were elucidated by spectroscopic analyses (HRESIMS and NMR). The absolute configurations of C-6 in the pyrone ring as well as the chiral carbons at the aliphatic side chain resulted from hydroxyl substitute were finally determined on the basis of measurement of ECD and Kusumi–Mosher method.