... Erptl. BioI. -Wed,, 67, 271 (1 944). (11) Another simplification of the morphine structure containing the essential structural features has been prepared by EL May and JG Murphy. J. Org. Chem., 20, 1197 (1955). ... Vol. IV, John Wiley and Sons. Inc., Ken- York, K. Y., 1963, p 702. ...