乙酸酐 、
4'c-benzyloxymethyl-(3'ar,10'atN1')-3'a,4',8',9'-tetrahydro-1'(3')H-spiro[[1,3]dithiane-2,10'-pyrrolo[1,2-c]purine]-2',6'-diamine 生成 4'
c-acetoxymethyl-1',3',5'-triacetyl-2',6'-bis-acetylimino-(3'a
r,10'a
tN1')-octahydro-spiro[[1,3]dithiane-2,10'-pyrrolo[1,2-
c]purine]