The most common and most likely answer to this crossword clue is the 9 letter word PEROXIDES
I've seen this crossword clue in The Guardian
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More clues leading to the result PEROXIDES
Buddy explains!

The straight part
We know that "compounds" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case compounds = peroxides.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PEROXIDES mean?
PEROXIDES noun- A divalent radical or anion containing two oxygen atoms linked by a covalent bond; any substance containing this group which yields hydrogen peroxide when treated with an acid
- Hydrogen peroxide, especially an aqueous solution used as a bleach
- Any unstable compound or general formula R-O-O-R'
- To treat (something) with hydrogen peroxide, especially hair in order to bleach it