I have a table called "gebaeude_salzburg" with all types of buildings in the city. 
In the following I want to use a Buffer around the central train station that has the osm_id="159867730" and a radius of 1000m. Then I want to select the building types "school" and "kindergarten" that are within this radius by intersecting them with the buffer. What I tried looks like this:

    WITH center AS (
         SELECT ST_Buffer(geom, 1000) FROM gebaeude_salzburg 
         WHERE osm_id='159867730')
    SELECT gebaeude_salzburg.name AS "Name der Einrichtung",
            ST_Distance(center.geom, gebaeude_salzburg) AS Distanz
    FROM gebaeude_salzburg, center
    WHERE (gebaeude_salzburg.type='school' OR gebaeude_salzburg.type='kindergarten')
    AND ST_Intersects(gebaeude_salzburg.geom,center.geom);

I get the following error: ERROR:  column center.geom does not exist
LINE 5: ST_Distance(center.geom, gebaeude_salzburg) AS Distanz
                    ^

can someone help? What am I doing wrong?