ORA-01031: insufficient privileges

able to describe but unable to select TEST_STRUCTURE
SQL>conn test/test
connected

SQL> select * from tab;

TNAME                          TABTYPE  CLUSTERID
------------------------------ ------- ----------
TEST_STRUCTURE              SYNONYM

SQL>desc TEST_STRUCTURE   <--- this works

SQL> select * from TEST_STRUCTURE          <-- this doesnt work

SQL> select * from TEST_STRUCTURE  
select * from TEST_STRUCTURE  
             *
ERROR at line 1:
ORA-01031: insufficient privileges


please advice