4 letters

moyl ∙

5 letters

enoyl aroyl croyl droyl

6 letters

oleoyl lipoyl xyloyl octoyl

7 letters

lauroyl quinoyl tropoyl caproyl pyrroyl anisoyl choloyl pantoyl toluoyl benzoyl ∙ gurgoyl

8 letters

hexanoyl butanoyl Alkanoyl ethanoyl ∙ decanoyl

9 letters

dibenzoyl propanoyl phthaloyl glutamoyl vanilloyl veratroyl cinnamoyl carbamoyl ∙

10 letters

triquinoyl camphoroyl anthranoyl

12 letters

anthraniloyl

14 letters

hydrocinnamoyl

19 letters

phenylthiocarbamoyl

Words with a ∙ are valid Scrabble words (SOWPODS word list)