α‐Pyrones and Pyranes from the Plant Pathogenic Fungus Pestalotiopsis scirpina

Three new α‐pyrones, scirpyrones A–C ( 1 – 3 ), and four new pyranes, scirpyranes A–D ( 4 – 7 ), were isolated from solid cultures of the plant pathogen Pestalotiopsis scirpina . Their structures were elucidated primarily by NMR experiments. The absolute configurations of C‐7 and C‐2′ in 1 , C‐7 in 2 , and C‐6 and C‐7 in 3 were deduced on the basis of circular dichroism (CD) data, whereas those of the secondary alcohols in 4 – 7 were determined by a modification of Mosher's method. Compound 1 is the first described 6‐(5‐oxotetrahydrofuran‐2‐yl)‐2 H ‐pyran‐2‐one. Compounds 4 – 6 showed significant cytotoxicity towards MCF‐7 cells.