Preparation of a lipid a derivative that contains a 27-hydroxyoctacosanoic acid moiety.

[structure: see text] A general synthetic strategy for long-chain omega-1 hydroxy fatty acids has been developed, which employs as a key reaction step a cross metathesis between omega-unsaturated ester and 3-butene-2-ol. The resulting lipids were used for the preparation of lipid A derivatives of Rhizobium sin-1, which have the ability to inhibit the E. coli LPS-dependent synthesis of tumor necrosis factor by human monocytes.