Compound 1

View in PubChem | MDL Molfile | ChemDraw

InChIKey PUUZNZCOKZPQRB-UHFFFAOYSA-N

Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.

4-Tritylphenyl octacosa-5,7,9,11,13,15-hexaynoate 5 (208 mg, 0.289 mmol) was dissolved in CH₂Cl₂ (15 mL), and MeOH (10 mL) was added. The flask was shielded from light with aluminum foil and NaOMe (31 mg, 0.578 mmol) was added. The resulting mixture was stirred for 30 min after which it was diluted with DCM, washed once with 1 m HCl and once with saturated NaCl solution. The organic phase was dried over Na₂SO₄, and concentrated in vacuo. Column chromatography (silica gel; DCM/n-pentane 1:1) yielded 1 as a yellow solution. For analytic purposes, CDCl₃ (10 mL) was added, and the mixture was concentrated in vacuo. To determine the yield, the organic phase was dried to afford methyl octacosa-5,7,9,11,13,15-hexaynoate 1 (119.8 mg, 0.289 mmol, 100%) as a yellow solid. For investigations at the air-water interface compounds that had been dried were purified again by column chromatography to ensure the integrity of the product (silica gel; DCM/n-pentane 1:1). ¹H NMR (400 MHz, CDCl₃): δ = 3.68 (s, 3H), 2.44 (t, J = 7.0 Hz, 2H), 2.42 (t, J = 6.8 Hz, 2H), 2.32 (t, J = 7.0 Hz, 2H), 1.88 (p, J = 7.1 Hz, 2H), 1.58-1.51 (m, 2H), 1.40-1.34 (m, 2H), 1.25 (m, 18H), 0.88 (t, J = 6.8 Hz, 3H). ¹³C NMR (101 MHz, CDCl₃): δ = 173.2, 82.2, 80.3, 66.6, 65.8, 63.0, 62.7, 62.5, 62.3, 61.9, 61.5, 60.9, 60.5, 51.9, 32.7, 32.1, 29.8, 29.7, 29.6, 29.5, 29.1, 29.0, 28.0, 23.2, 22.8, 19.7, 19.1, 14.3. HRMS (APPI): calcd for C₂₉H₃₄O₂: 414.2559 ([M]⁺); found: 414.2552. R_f: 0.56 (DCM/n-heptane 4:1).