Alylene or Allylene: How To spell?

The word Alylene is misspelled against Allylene, a noun meaning "A gaseous hydrocarbon, C3H4, homologous with acetylene; propine."

Allylene has double "ll" is mispronounced as "l"
Remember double 'LL' in between the strings a & ylene which should not be misspelled with single 'L'
Wrong Spelling:  a-l-ylene 
Correct Spelling:  a-ll-ylene 
Explore spell check of Allylene to spell without errors.