Synthesis of 2-deoxy-2-fluoro analogs of polyprenyl β-d-arabinofuranosyl phosphates

Described is the synthesis of polyprenyl 2-deoxy-2-fluoro-β-d-arabinofuranosyl phosphate derivatives, including an analog of decaprenyl β-d-arabinofuranosyl phosphate, the donor species used by the arabinosyltransferases involved in mycobacterial cell-wall biosynthesis. The targets were synthesized via a route involving the synthesis of a protected β-d-arabinofuranosyl phosphate derivative, its coupling with a polyprenyl trichloroacetimidate, and then deprotection of the resulting product. The use of arabinofuranosyl phosphates with the monosaccharide hydroxyl groups protected as either silyl ethers or benzoate esters was explored. Although the coupling yields between the phosphate and polyprenyl trichloroacetimidates were comparable with either type of protecting group, access to the benzoyl-protected derivative was more efficient and therefore gave the products in higher overall yield.