Saponification of ethyl adamantyloxyacetate (I), followed by treatment of the resultant carboxylic acid (II) with oxalyl chloride gives rise to acid chloride (III). This is then condensed with benzyl (triphenylphosphoranylidene)acetate (IV) to produce the phosphoranylidene keto ester (V). Subsequent oxidative cleavage of phosphorane (V) with oxone under phase transfer conditions leads to diketo ester (VI). Cyclization between diketo ester (VI), cyclohexanecarboxaldehyde (VII) and ammonium acetate in hot AcOH affords imidazole (VIII). The benzyl ester group of (VIII) is removed by catalytic hydrogenolysis, yielding acid (IX), which is further coupled with benzyl 3-aminobenzoate (X) to furnish amide (XI). Finally, benzyl ester hydrogenolysis in the presence of Pd/C provides the target compound (1,2).

Saponification of ethyl adamantyloxyacetate (I), followed by treatment of the resultant carboxylic acid (II) with oxalyl chloride gives rise to acid chloride (III). This is then condensed with benzyl (triphenylphosphoranylidene)acetate (IV) to produce the phosphoranylidene keto ester (V). Subsequent oxidative cleavage of phosphorane (V) with oxone under phase transfer conditions leads to diketo ester (VI). Cyclization between diketo ester (VI), cyclohexanecarboxaldehyde (VII) and ammonium acetate in hot AcOH affords imidazole (VIII). The benzyl ester group of (VIII) is removed by catalytic hydrogenolysis, yielding acid (IX), which is further coupled with benzyl 3-aminobenzoate (X) to furnish amide (XI). Finally, benzyl ester hydrogenolysis in the presence of Pd/C provides the target compound (1,2).