Partial benzoylation of the 3,4-dibenzyl ethers of d- and l-chiro-inositol provided the 1,2,5-tri-O-benzoyl-3,4-di-O-benzyl-chiro-inositols. Inversion of the free axial hydroxyl group gave a mixture of chiral 1,3,4- and 1,2,4-tri-O-benzoyl-5,6-di-O-benzyl-myo-inositols [W. Tegge and C. E. Ballou, Proc. Natl. Acad. Sci. U.S.A., 86 (1989) 94-98]. Catalytic hydrogenolysis cleaved the benzyl ether groups of the 1,3,4-tri-O-benzoyl-5,6-di-O-benzyl-myo-inositols (d- and l-) to yield the 1,3,4-tri-O-benzoyl-myo-inositols, which were phosphorylated by a dibenzyl phosphoramidite method. Removal of all blocking groups gave the pure enantiomeric myo-inositol 2,4,5-trisphosphates. Syntheses of the chiro-inositol 1,3,4-trisphosphates, which are analogs of the myo-inositol 1,4,5-trisphosphates having an axial phosphate group at position 1, or analogs of the myo-inositol 2,4,5-triphosphates having an axial hydroxyl at position 1, were also devised starting with the 1,2,5-tri-O-benzoyl-3,4-di-O-benzyl-chiro-inositols. In a calcium-release assay with saponin-permeabilized rat basophilic leukemia cells, the d isomers of both of these analogs had EC50 values of 4μm, compared with a value of 0.17 μm for d-myo-inositol 1,4,5-trisphosphate, whereas the l isomers had EC50 values of about 100μm. © 1991.
Tegge, W., Denis, G. V., & Ballou, C. E. (1991). Synthesis and Ca2+-release activity of d- and l-myo-inositol 2,4,5-trisphosphate and d- and l-chiro-inositol 1,3,4-trisphosphate. Carbohydrate Research, 217(C), 107–116. https://doi.org/10.1016/0008-6215(91)84121-T