116822-48-1
→
112167-94-9
methyl 6,9-dioxadispiro[3.0.45.34]dodec-2-ene-3-carboxylate
4934-95-6
(2-氧代环戊基)-乙酸甲酯
66806-62-0
methyl 2-(1,4-dioxaspiro[4.4]nonan-9-yl)acetate