| Poly(cyclic urea) compounds were synthesized and tested as substitutes of hexamethylphosphoramide (HMPA). HMPA is a potent carcinogen but demonstrates excellent properties as an additive in organometal chemistry. The poly(cyclic urea), which showed similar properties to HMPA in solution, was attached to a variety of resins in an effort to create a new polymer-supported reagent. Polymer-supported HMPA was also prepared by suspension polymerization. In diverse reactions, these reagents showed very similar properties to HMPA, were easily removed by filtration and could be recycled without loss of chemical activity.; Highly functionalized spiroketals were designed and synthesized as mimics of calyculin A, a known protein phosphatase inhibitor. Regio- and stereoselective reductions, hetero-Diels-Alder reactions and spiroketalizations gave eight diastereomeric spiroketal compounds. Additionally, through asymmetric crotylations, phosphorylations and cross-metathesis, a series of new phosphoric acid compounds were also synthesized. |
