Graduation date: 1994

A novel acyl protecting group for cytosine and adenine has been prepared from 4-( chloromethyl) benzoic acid. Reaction of the acid with morpholine produces 4-( 4-morpholinyl )methyl benzoic acid which is converted to it's acid chloride with thionyl chloride. This may be used to acylate cytidine and adenosine under standard conditions. This ionizable protecting group has the ability to solublize protected oligomers, which allows their purification with ion-exchange chromatography on S-Sepharose. Solid phase synthesis has been performed using this protecting group on morpholine nucleosides. Morpholine nucleoside carbamates were synthesized in high yields. The results revealed that high purities of the hexamers were obtained. These hexamers, which have the protecting groups intact, provide the potential for further segment condensation to make large size oligonucleotide analogues. The success of the solid phase synthesis was dependent upon use of a selectively cleavable anchor which allowed the finished oligomer to be released from the resin with protecting groups intact. Attempts to modify the anchor to make it more efficient were unsuccessful. It was found that DBU degrades derivatized polystyrene resin and should not be used at early stages in solid phase synthesis. / Graduation date: 1992