2-Fluoro-2-deoxy-lns(1,4,5)Ps (2) and 2,2-difluoro-Z-deoxy-Ins(l,4,5)P, (3) were synthesized from protected inositol precursors. The monofluoro compound with free 3,6-hydroxyl groups underwent slow defluorination at pH 1 13, as determined by laF-NMR, while the difluoro compound was inert. Cells can communicate with one another in a number of ways. 1 For example, external messengers (hormones, growth factors, etc.) can bind to external receptors on a target cell, activating a second messenger system.2 A recently discovered second messenger is my@inositol-1,4,5-trisphosphate? (2) which arises from cleavage of a cell membrane component, phosphatidyl inositoL4,5bisphosphate, by a G protein-activated phospholipase C.4 Once released, the Ins(l,4,5)P, binds to specific receptors on the endoplasmic reticulum and stimulates the release of calcium from intracellular storage sites. 2 3 Fluorodeoxy sugars are molecules in which a C-OH is replaced by a C-F. Bond lengths and polarization are similar in both groups: however, the C-F bond can only accept but not donate a hydrogen bond.5 Such compounds are potentially useful as probes for studies of the active site of enzymes and for membrane transport studies. Several fluorodeoxy inositolss and a 2-deoxy-2-fluoro-1 -phosphatidyl-scy//oinositolee have been reported. Recently, we reported the synthesis of 2-fluoro and 2,2-difluoro-2-deoxy