合成路线1

Conjugate addition of tolylmagnesium bromide (II) to ecgonidine methyl ester (I) provided the 3-beta-tolyl tropane derivative (III). N-Dealkylation of (III) to produce the nortropane analogue (V) was carried out via acylation with trichloroethyl chloroformate, followed by reductive cleavage of the resultant trichloroethyl carbamate (IV) with Zn and HOAc. Alkylation of the secondary amine (V) with propargyl bromide (VI) afforded the corresponding propargyl amine (VII). Subsequent hydrostannylation of the propargyl group furnished the desired (E)-stannylpropenyl compound (VIII) along with the corresponding (Z)-isomer. In an improved procedure, amine (V) was alkylated with (E)-3-chloro-1-(tributylstannyl)-1-propene (IX) to yield pure (VIII). Finally, the title vinyl iodide was obtained by iododestannylation of (VIII) employing iodine in cold CHCl3.