G. (5R,5aR,8aR,9S)-9-[(2,3-diformyl-4,6-0-(R)-ethyliden-β-D-glukopyranosyl)oxy]-5-{4-[(benzyloxykarbonyl)oxy]-3,5-dimethoxyfenyl}-5,8,8a,9-tetrahydroisobenzofuro[5,6-f] [1,3]benzodioxol-6(5aH)-on (4 ˊ-karbobenzoyloxydiformylethylidenlignan P),