1,2-O-isopropylidene-5-O-(triphenylmethyl)-α-D-erythro-pentofuranos-3-ulose

(4S,7R,7aR)-4,7-bis(ethoxycarbonyloxy)-4,5,7,7a-tetrahydro-2H-furo[2,3-c]pyran-2-one

(4S,7S,7aR)-4,7-diacetoxy-4,5,7,7a-tetrahydro-2H-furo[2,3-c]pyran-2-one

3-hydroxypyran-4-thione

ethyl 5-(dimethylamino)methylene-4-[2-(dimethylamino)vinyl]-2-oxo-2,5-dihydrofuran-3-carboxylate