CREATE TABLE table_2417345_4 (reason_for_change VARCHAR, vacator VARCHAR)

Name the reason for change when George W. Greene (D) was the vacator.
SELECT reason_for_change FROM table_2417345_4 WHERE vacator = "George W. Greene (D)"
SELECT "reason_for_change" FROM "table_2417345_4" WHERE "George W. Greene (D)" = "vacator"