Aldol condensation between dimethyl 1,3-acetonedicarboxylate (I) and 3,5-heptanedione (II) produced dimethyl 4,6-diethyl-2-hydroxy-1,3-benzenedicarboxylate (III). After conversion of phenol (III) to the corresponding aryl triflate (IV), Suzuki coupling with 4-fluorobenzeneboronic acid (V) yielded the biphenyl derivative (VI). The diisopropyl compound (VII) was then obtained by methylation of (VI) at the benzylic position using iodomethane and LDA. Partial reduction of diester (VII) with Red-Al?gave rise to the hydroxy ester (VIII), which was further oxidized to aldehyde (IX) by treatment with pyridinium chlorochromate. Wittig reaction of aldehyde (IX) with ethyl triphenylphosphonium bromide furnished the propenyl compound (X)
The ester group of (X) was reduced to alcohol (XI) employing LiAlH4 in boiling THF. Subsequent olefin hydrogenation in the presence of Pd/C produced the propyl compound (XII). After oxidation of the primary alcohol (XII) to aldehyde (XIII) by means of pyridinium chlorochromate, addition of methylmagnesium bromide led to the desired secondary alcohol (1,2).