SYNTHESIS OF (+/-)-MYO-INOSITOL 1,4,5-TRISPHOSPHATE AND THE NOVEL ANALOG (+/-)-MYO-INOSITOL 1,4-BISPHOSPHATE 5-PHOSPHOROTHIOATE

Novel routes to myo-inositol 1,4,5-trisphosphate and a phosphorothioate analogue involving mixed P(V) and P(III) chemistry have been developed. Phosphorylation of 2,3,6-tri-O-benzyl-myo-inositol 1-[di-(2,2,2-trichloroethyl) phosphate] with bis(2,2,2-trichloroethyl) phosphorochloridate gave a mixture of the 1,4- and 1,5-bisphosphate derivatives from which the 1,4-bis[di-(2,2,2-trichloroethyl) phosphate] 9 crystallised. Phosphitylation of HO-5 in 9 followed by oxidation yielded the 1,4-bis[di-(2,2,2-trichloroethyl) phosphate] 5-[di-(2-cyanoethyl) phosphate] which was deblocked using sodium in liquid ammonia to give (+/-)-myo-inositol 1,4,5-trisphosphate. Phosphitylation of HO-5 in 9 followed by sulphoxidation generated the 1,4-bis[di-(2,2,2-trichloroethyl) phosphate] 5-[di-(2-cyanoethyl) thiophosphate] which was deblocked to give (+/-)-myo-inositol 1,4-bisphosphate 5-phosphorothioate. Removal of the 2,2,2-trichloroethyl group, using sodium in liquid ammonia, represents a new method for removing this protecting group.