.gamma.-Lactone of ribonic acid 5336-08-3 D-RIBONOLACTONE D-Ribonic acid, .gamma.-lactone D-Ribono-.gamma.-lactone D-Ribono-1,4-lactone D-Ribopentono-1,4-lactone NSC1031 Ribonic acid, .gamma.-lactone, D- Ribono-.gamma.-lactone