py.ran

n.（名詞）
Either of two isomeric compounds with the formula C5H 'O, having a ring of five carbon atoms and one oxygen atom.
吡喃：化學(xué)分子式是C5H 'O的兩種同分異構(gòu)化合物中的任一種，且有五個(gè)碳原子和一個(gè)氧原子構(gòu)成的環(huán)狀物

來源：
pyrone [heterocyclic compound] pyr(o)- -one
pyrone [雜環(huán)化合物] pyr(o)- -one
-an 2
-an2