合成路线1

3) The acylation of D-aspartic acid (I) with methyl chloroformate and NaOH in water yields N-(methoxycarbonyl)-D-aspartic acid (II), which is anhydrized with oxalyl chloride and DMF in isopropyl acetate giving the corresponding anhydride (III). The Friedel-Craft's condensation of (III) with 2-chloroanisole (IV) by means of AlCl3 in nitromethane - dichloromethane affords 3-(3-chloro-4-methoxybenzoyl)-N-(methoxycarbonyl)-D-alanine (V), which is reduced with H2 over Pd/C in aqueous acetic acid to the substituted amino acid (VI). The reaction of (VI) with PCl5 or oxalyl chloride yields the corresponding acyl chloride (VII), which is cyclized by means of FeCl3 in nitromethane-dichloromethane affording 7-methoxy-2(R)-(methoxycarbonylamino)-1-tetralone (VIII). The reduction of (VIII) with sodium bis(methoxyethoxy) aluminum hydride (BMAlH) in toluene gives the trans-aminoalcohol (IX), which is deprotected by treatment with NaOH in methanol - water yielding (2R-trans)-2-amino-1-hydroxy-7-methoxytetraline (X). The acylation of (X) with propionyl anhydride in methanol - water affords the amide (XI), which is reduced with BH3-dimethyl sulfide giving [2(R)-trans]-1-hydroxy-7-methoxy-2-(propylamino)tetraline (XII). The acylation of (XII) with chloroacetyl chloride in toluene - aqueous Na2CO3 affords the chloroacetamide (XIII), which is cyclized by means of NaOH and tetrabutylammonium chloride to give [4a(R)-trans]-9-methoxy-4-propyl-3,4,4a,5,6,10b-hexahydro-2H-naphth [1,2-b]-1,4-oxazin-3-one (XIV). The reduction of (XIV) with BMAlH as before gives the methylated product (XV), which is finally demethylated with BBr3 and cyclohexene in dichloromethane.