H. (5R,5aR,8aR,9S)-9-ethoxy-5-(4-hydroxy-3,5-dimethoxyfenyl)-5,8,8a,9-tetrahydroisobenzofuro[5,6-f] [1,3]benzodioxol-6(5aR)-on (4'-0-demethyl-l-0-ethylepipodofylotoxin),