The sililation of 4-methyl-1-octin-4-ol (I) with trimethylsilyl chloride by means of triethylamine in DMF gives the corresponding silyloxy derivative (II), which is treated with diisobutyl aluminum hydride and I2 in toluene - THF yielding 4-methyl-(RS)-4-trimethylsilyloxy-trans-1-octene-1-yl iodide (III). The condensation of (III) with the complex of copper 1-pentynilyde and HMPT (IV) by means of butyllithium in hexane affords the complex salt (V), which, without isolation, is allowed to react with methyl 7-[3-[(RS)-tetrahydropyranyl-2-oxy]-5-oxo-1-cyclopentenyl]-heptanoate (VI) in ethyl ether to give methyl 7-[3-(tetrahydropyranyl-2-oxy)-2-(4-methyl-4-trimethylsilyloxy-trans-1-octene-1-yl)-5-oxo-cyclopentyl]heptanoate (VII). Finally, this compound is hydrolyzed with a mixture acetic acid - water - THF at room temperature.

The sililation of 4-methyl-1-octin-4-ol (I) with trimethylsilyl chloride by means of triethylamine in DMF gives the corresponding silyloxy derivative (II), which is treated with diisobutyl aluminum hydride and I2 in toluene - THF yielding 4-methyl-(RS)-4-trimethylsilyloxy-trans-1-octene-1-yl iodide (III). The condensation of (III) with the complex of copper 1-pentynilyde and HMPT (IV) by means of butyllithium in hexane affords the complex salt (V), which, without isolation, is allowed to react with methyl 7-[3-[(RS)-tetrahydropyranyl-2-oxy]-5-oxo-1-cyclopentenyl]-heptanoate (VI) in ethyl ether to give methyl 7-[3-(tetrahydropyranyl-2-oxy)-2-(4-methyl-4-trimethylsilyloxy-trans-1-octene-1-yl)-5-oxo-cyclopentyl]heptanoate (VII). Finally, this compound is hydrolyzed with a mixture acetic acid - water - THF at room temperature.

The sililation of 4-methyl-1-octin-4-ol (I) with trimethylsilyl chloride by means of triethylamine in DMF gives the corresponding silyloxy derivative (II), which is treated with diisobutyl aluminum hydride and I2 in toluene - THF yielding 4-methyl-(RS)-4-trimethylsilyloxy-trans-1-octene-1-yl iodide (III). The condensation of (III) with the complex of copper 1-pentynilyde and HMPT (IV) by means of butyllithium in hexane affords the complex salt (V), which, without isolation, is allowed to react with methyl 7-[3-[(RS)-tetrahydropyranyl-2-oxy]-5-oxo-1-cyclopentenyl]-heptanoate (VI) in ethyl ether to give methyl 7-[3-(tetrahydropyranyl-2-oxy)-2-(4-methyl-4-trimethylsilyloxy-trans-1-octene-1-yl)-5-oxo-cyclopentyl]heptanoate (VII). Finally, this compound is hydrolyzed with a mixture acetic acid - water - THF at room temperature.