4-methoxy-1-oxaspiro[4.5]dec-3-en-2-one

3-(but-2-enoyl)-4-methoxy-1-oxaspiro[4.5]dec-3-en-2-one

1-[(2e)-1-氧代-2-丁烯]-L-脯氨酸

benzyl but-3-enoate

N-benzylbut-2-enamide