Arylpentanone (I), which was in equilibrium with its hemiacetal cyclic form, was alkylated with isopropyl 5-bromo-2,2-dimethyl-pentanoate (II) in the presence of NaH to afford ether (III). After saponification of the isopropyl and acetate esters of (III) with ethanolic KOH, the resulting ketoacid (IV) was reduced with NaBH4 to yield hydroxyacid (V). Finally, cyclization of (V) using 2,2'-dipyridyl disulfide, triphenylphosphine and silver perchlorate produced the target macrocyclic lactone.

Arylbutanone (I), which was in equilibrium with its hemiacetal cyclic form, was alkylated with isopropyl 5-bromo-2,2-dimethyl-pentanoate (II) in the presence of NaH to afford ether (III). After saponification of the isopropyl and acetate esters of (III) with ethanolic KOH, the resulting ketoacid (IV) was reduced with NaBH4 to yield hydroxyacid (V). Finally, cyclization of (V) using 2,2'-dipyridyl disulfide, triphenylphosphine and silver perchlorate produced the target macrocyclic lactone.