how do i convert an uncompressed key to an extended bip 32?
With "uncompressed key" you probably refers to an uncompressed public-key.

An extended public-key has additional informations (next to the compressed public-key itself).
You can get the pure compressed public key from an extended public key, but not vice-versa.  


depth (in the hierarchy)
child-index
chaincode (the hierarchal link)
fingerprint (first 4 bytes of the keyId [ripemd(sha256())])