描述:
(2R,3aS,3a'R,6S,7R,7aR,7'R,7a'S)-7-(benzyloxy)-6-(((2S,3S,4S,5R,6R)-4-(benzyloxy)-5-hydroxy-3-methoxy-6-(methoxymethyl)tetrahydro-2H-pyran-2-yl)oxy)octahydro-4H-2,4'-spirobi[[1,3]dioxolo[4,5-c]pyran]-7'-yl 2,4-bis(benzyloxy)-6-methylbenzoate 、 在
作用下,
以55的产率得到