CREATE TEMP TABLE AS ... ON COMMIT DROP fails

I need to create temporary table with data which is dropped at end of
transaction.

CREATE TABLE t1 ( c1 INTEGER ) ;
INSERT INTO t1 VALUES (1);
CREATE TEMP TABLE t2 AS SELECT * FROM t1 ON COMMIT DROP;

Causes ERROR:  syntax error at or near "ON" at character 104

How to implement this ?

Andrus.