pentamethyl

例句：

1. 1.This compound is made from pentamethylcyclopentadiene.
   这种化合物是由五甲基环戊二烯制成的。
2. 2.The pentamethylcyclopentadiene is a key intermediate in the synthesis of nylon-6.
   五甲基环戊二烯是尼龙-6合成的关键中间体。
3. 3. The pentamethylcyclopentadiene is used as a precursor in the production of polyesters and other polymers.
   五甲基环戊二烯用作聚酯和其他聚合物生产的前体。