合成路线1

Synthesis of the perhydroindole intermediate (XIII): The alkylation of the N-protected glutamate (I) with allyl bromide (II) by means of LiHMDS in THF gives the protected chiral allyl glutamate (III) (1), which is cyclized by means of TFA in dichloromethane to yield the pyroglutamate (IV). The reduction of (IV) with LiHBEt3 in THF affords the hydroxy compound (V), which is treated with Ac2O and DMAP in dichloromethane to provide the expected hemiaminal derivative (VI). The reaction of (VI) with allyl tributylstannane (VII) by means of BF3/Et2O in toluene gives the diallyl pyrrolidine (VIII), which is submitted to a ring closure by olefin metathesis using a Grubbs Ru catalyst in dichloromethane to yield the hexahydroindole derivative (IX). The reaction of (IX) with mCPBA in dichloromethane affords the epoxide (X), which is hydrolyzed with TFA to yield the dihydroxy compound (XI). The reaction of (XI) with Mom-Cl and DIEA in dichloromethane provides the bis mom ether (XII), which is treated with H2 over Pd/C in methanol to yield the desired perhydroindole intermediate (XIII) (2).