Three new 16-norphragmalin limonoids, chukvelutins A-C (1-3), were isolated from the stem bark of Chukrasia tabularis var. velutina, which possess unprecedented skeletons, featured with a characteristic ketal moiety between the phragmalin skeleton and a biosynthetically extended isobutyryl group at C-15. Their structures were elucidated by extensive spectroscopic technologies.