[PL/SQL]EXECUTE IMMEDIATE CREATE INDEX is failing with invalid CREATE INDEX option

For every table_name I need to create index based on index_required returned from specified query I wrote below PL/SQL Procedure:

DECLARE
  sIndexRequired  VARCHAR(50);
  sTableName      VARCHAR(50);
  cSQL             CLOB ;
BEGIN

  FOR r IN [...] --I'm getting index_required and table_name from here
    
  LOOP
    
        sIndexRequired := r.index_required;
        sTableName     := r.table_name;
        
       EXECUTE IMMEDIATE 'CREATE INDEX ' || sTableName || 
        CASE WHEN sIndexRequired = 'XXX'  THEN '_YYY' 
             [...] -- more case when cases
        END
        || ' ON ' || sTableName || ' (' || sIndexRequired || ') TABLESPACE xyz;';
        
  END LOOP;
  END;
/

But it's failing with

Error report -
ORA-02158: invalid CREATE INDEX option
ORA-06512: at line 46
ORA-06512: at line 46
02158. 00000 -  "invalid CREATE INDEX option"
*Cause:    An option other than COMPRESS, NOCOMPRESS, PCTFREE, INITRANS,
           MAXTRANS, STORAGE, TABLESPACE, PARALLEL, NOPARALLEL, RECOVERABLE,
           UNRECOVERABLE, LOGGING, NOLOGGING, LOCAL, or GLOBAL was specified.
*Action:   Choose one of the valid CREATE INDEX options.

Can anyone has idea how can I get this work?

Thanks, Michał

Currently, you're blind and have no idea what you are doing.

Instead of EXECUTE IMMEDIATE,

• declare local VARCHAR2 variable large enough to contain the whole CREATE INDEX statement
• compose the statement and put it into the variable
• display its contents on the screen (use DBMS_OUTPUT.PUT_LINE)
• copy/paste it and execute it
  • if it is not clear what's wrong at the first sight, Oracle will now tell you what went wrong. If you use SQL*Plus, an asterisk * will point exactly to the failing spot
• fix the error
• run the procedure again

Once you're sure that you did it right, remove print to screen and use EXECUTE IMMEDIATE.

As commented, it turns out that it was the trailing semi-colon within EXECUTE IMMEDIATE that caused problems.

No : || ') TABLESPACE xyz;';
Yes: || ') TABLESPACE xyz';