Cyclic Monophosphates and Their Analogues

2 Cyclic Monophosphates and Their Analogues. - A new preparative route to cyclic phosphorothioates of type 199 involves the reaction of 5 -0-Dmtr-nucleo-sides with diphenyl H-phosphonate in the presence of pyridine, followed by treatment of the resultant cyclic H-phosphonates with sulfur and final deprotection with acetic acid. The method was used with all four ribonucleobases, and gave the products as 1 1 mixtures of diastereoisomers.  

The phosphinic acid analogue 200 of cyclic AMP has been prepared by linking adenine to a cyclic methyl phosphinate derived from di-O-isopropylidene-glucose (Chapter 17). Thymidine cyclic 3, 5 -phosphorofluoridate and its sulfur analogue (201, X = O or S), as 1 1 mixtures of diastereomers, have been prepared by oxidation or sulfurization of the cyclic phosphorofluoridite. 7-Deoxypac-litaxel has been linked to cyclic AMP as a phosphotriester the product showed enhanced cytotoxicity against human cancer cells.  

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