To a solution of 12.5 g (50 mmol) (E,E)-4,8,12-trimethyl-trideca-3,7,11-trienoic acid (isomeric purity of 95%) [K. Ishihara et al., J. Am. Chem. Soc. 2002, 124, 3647-3655] in 100 ml methyl tert-butyl ether (MTBE) were added at r.t. 8.35 g (50 mmol) (R)-(−)-mandelic acid methyl ester, [α]D=−147.3 (c=1.0, MeOH), and 1.5 g 4-dimethylaminopyridine (DMAP). After stirring for 15 min at 28° C., 10.5 g (51 mmol) N,N′-dicyclohexylcarbodiimide (DCC) were added, during which the temperature raised to 35° C. The reaction mixture was stirred for 1.5 h at 38-40° C., cooled to r.t. and filtered. The resulting solution was concentrated in vacuo. The residue (23.1 g) was purified over 100 g silicagel, elution of the product with hexane/MTBE 1:1. Concentration of the combined fractions in vacuo and drying of the product in high vacuo (50° C./0.08 Torr) afforded 19.5 g (97%) of (E,E)-4,8,12-trimethyl-trideca-3,7,11-trienoic acid (R)-methoxycarbonyl-phenyl-methyl ester (1) in form of a colorless oil.
