合成路线1

The reaction of 2(R)-(acetoxymethyl)-5-methyl-3(E)-hexen-1-ol (I) with MsCl and TEA in dichloromethane gives the mesylate (II), which is treated with NaN3 in hot DMF to yield the azido derivative (III). The hydrolysis of (III) catalyzed by Pseudomonas cepacia affords the azido alcohol (IV), which is reduced with PPh3 in THF/water to provide the aminoalcohol (V). The N-protection of (V) by means of Boc-ON and Et3N gives the carbamate (VI), which is O-protected by means of Tips-Cl and imidazole yielding the silyl ether (VII). The alkylation of the carbamate (VII) with allyl bromide (VIII) and NaH in DMF affords the allyl carbamate (IX), which is submitted to a ring closure metathesis reaction catalyzed by Grubb's catalyst to provide the chiral tetrahydropyridine (X). The desilylation of (X) by means of TBAF in THF gives N-(tert-butoxycarbonyl)-3(R)-(hydroxymethyl)-1,2,3,6-tetrahydropyridine (XI), which is treated with mCPBA in dichloromethane to yield an inseparable diastereomeric mixture of epoxides (XII) + (XIII). Finally, this mixture is treated with either HClO4 in acetone, HCl in ethyl acetate or with refluxing aq. KOH to afford separable mixtures of the target isofagomine and (XIV), one of its diastereomers.