Shop at anew to get the chemical substance (6)
I believe the answer is:
potash
'the chemical substance' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'shop at anew' is the wordplay.
'anew' indicates an anagram.
'shop'+'at'='shopat'
'shopat' anagrammed gives 'POTASH'.
'to get' is the link.
Can you help me to learn more?
(Other definitions for potash that I've seen before include "Powerful alkali used in gardening" , "Strong alkali derived from burnt wood" , "Potassium compound used in agriculture and industry" , "Type of fertiliser" , "Powerful alkali from burnt wood" .)