2-oxa-3-oxo-6-syn-acetoxymethyl-7-anti-hydroxy-cis-bicyclo[3,3,0]octane

3,4-二氢-2H-吡喃

3,3A,6,6A-四氢-2H-环戊二烯并[b]呋喃-2-酮

甲醛