An efficient method for the synthesis of unsymmetrical lipid-based O,O-dialkylphosphites is reported. The reaction implies the use of H-phosphonates monoester ammonium salt which is coupled with a fatty alcohol in the presence of an optimized quantity of pivaloyl chloride (Piv-Cl) as coupling reagent. The reaction conditions offer access to a wide panel of unsymmetrical O,O-dialkylphosphites including either non-functionalized lipid derivatives (lauryl, dodecyl tetradecyl, hexadecyl, octadecyl), ramified lipid (phytanyl), unsaturated lipids (oleyl, linoleyl) or ω-functionalized alkyl alcohols (azide, propargyl, alkenyl).