A solution of the diol (6Z,9Z,29Z,32Z)-octatriaconta-6,9,29,32-tetraene-18,20-diol (7) (940 mg, 1.68 mmol) and 3-chloropropionaldehyde diethylacetal (563 μL, 3.36 mmol) in toluene (15 mL) was treated with PPTS (50 mg) and heated (80° C., 2 h). After cooling (rt) the reaction mixture was poured into sat. aq. NaHCO3, extracted with EtOAc, washed with brine, dried (Na2SO4), filtered and concentrated. The crude product was dissolved in a solution of (CH3)2NH (25 mL, 5.6M in EtOH), transferred to a sealed reaction vessel and heated (80° C., 16 h). Once complete the yellow solution was concentrated and the residue was subjected to chromatography (100% EtOAc) to yield 2-(4-((8Z,11Z)-heptadeca-8,11-dien-1-yl)-6-((9Z,12Z)-octadeca-9,12-dien-1-yl)-1,3-dioxan-2-yl)-N,N-dimethylethanamine (8) (585 mg, 54% over 2 steps) as a pale yellow oil. Rf 0.5 (10% CH3OH—CH2Cl2); 1H NMR (400 MHz, CDCl3) 5.46-5.29 (m, 8H), 4.85 (t, 0.5H), 4.59 (t, 0.5H), 4.08-3.98 (m, 0.5H), 3.80-3.70 (m, 0.5H), 3.60-3.50 (m, 1H), 2.78 (app. t, 4H), 2.50-2.37 (m, 2H), 2.32-2.21 (m, 6H), 2.13-2.02 (m, 8H), 1.88-1.72 (m, 2H), 1.63-1.22 (m, 40H), 0.91 (t, 6H). FW 643.47, C43H79NO2.
