合成路线1

A new synthesis of (-)-15-deoxyspergualin has been reported: The hydrolysis of 7-bromoheptanenitrile (I) with HCl gives the corresponding amide (II), which by reaction with sodium azide yields 7-azidoheptanamide (III). The condensation of (III) with 2-hydroxy-2-methoxyacetic acid methyl ester (IV) affords the alpha-hydroxyglycine derivative (V), which is condensed with 1(S)-(2-naphthyl)ethanol (VI) by means of SO2Cl2 and triethylamine in dichloromethane providing the diastereomeric mixture (VII). Hydrolysis of the ester group of (VII) with NaOH yields the corresponding free acid (VIII), which is condensed with the diprotected triamine (IX) by means of DCC and HOBt in dichloromethane affording a diastereomeric mixture of diamides. This mixture is separated by flash chromatography giving the desired diastereomer (X). The condensation of (X) with the protected isothiourea (XI) by means of triphenylphosphine in THF/water provides the proteted guanidino derivative (XII), which is finally deprotected by hydrogenation with H2 over Pd/C in methanol/acetic acid.