合成路线1

In an alternative procedure, aldehyde (II) was condensed with the indoloazepine (VIII) bearing a chiral N-alpha-ferrocenylethyl substituent to provide an equimolecular mixture of two separable C-20 epimeric diastereomers (IX) and (X), each accompanied by a minor diastereoisomeric byproduct. Cleavage of the ferrocenyl substituent with HOAc at 70 C provided the secondary amines (XI) and (XII). In this cleavage, the C-3,C-7 epimeric products were formed in 12% yield and were separated by chromatography. The major secondary amines (XI) and (XII) were N-benzylated to provide the corresponding tertiary amines (XIII). Reductive ring cleavage, followed by hydrogenolysis of the N-benzyl group, then gave the tricyclic compounds (VI), which were cyclized and rearranged as above.