Design Compiler Using a library during synthesis

[Lightning19]

Hello,

I downloaded an AES package off of OpenCores, and am trying to synthesize it with Design Compiler.

I am currently trying to synthesize a file key_expansion.vhdl with

read_vhdl "key_expansion.vhdl"

However I am getting an error message

[Failure] Entity declaration KEY_EXPANSION not found in library WORK
*** Presto compilation was unsuccessful. ***
Error: Can't read 'vhdl' file '/...l/keyexp/key_expansion.vhdl'. (UID-59)


At the top of the key_expansion.vhdl file, there is

library WORK;
use WORK.aes_pkg.ALL;

and there is a directory called work that contains an aes_pkg directory with .dat, .dbs, and .prw files.

How can I get Design Compiler to recognize these files so that it can synthesize this file?

I have tried

define_design_lib WORK –path ./work

but unfortunately this did not correct the problem.

Thanks.