An advanced intermediate related to the structures of CP-225,917 and CP-263,114 was constructed by a sequence based on the use of Grob-like fragmentation, intramolecular conjugate displacement, and [2,3]-Wittig rearrangement. A variant of the [2,3]-Wittig rearrangement was developed.

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Two general methods are explored for the stereoselective synthesis of exo-glycals. One method utilizes a nucleophilic addition of fully protected sugar lactones of gluco-, galacto-, and manno-types, followed by the subsequent dehydration, to give the desired exo-glycals with (Z)-configuration. The other method proceeds with selenylation of C-glycosides in a stereoselective manner. The subsequent selenoxide elimination also provides (Z)-exo-glycals. The prepared exo-glycal conjugated esters of either gluco- or manno-type react with allyl alcohol to give exclusively alpha-anomers.

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In memoriam Professor Hanns FischerThe synthesis of a new sterically highly hindered 7-membered alkoxyamine, 2,2,7,7-tetraethyl-1-(1-phenylethoxy)-1,4-diazepan-5-one (4), starting from known 2,2,6,6-tetraethyl-1-(1-phenylethoxy)piperidin-4-one (3) via a Beckmann-type rearrangement is presented. It is shown that ring-enlargement by insertion of an NH moiety in going from 3 to 4 leads to a more efficient regulator for nitroxide-mediated controlled living radical styrene (= ethenylbenzene) and butyl acrylate (= butyl prop-2-enoate) polymerization. In addition to the polymerization experiments, kinetic data on the reversible CÀO bond homolysis of alkoxyamines 3 and 4 are presented. . In NMP, chain-growing polymer radicals and the corresponding nitroxides are reversibly formed via clean thermal CÀO bond homolysis. As example, a 2,2,6,6-tetramethylpiperidin-1-yloxy radicalmediated (TEMPO-mediated) styrene (= ethenylbenzene) polymerization is presented in Scheme 1. Importantly, the equilibrium between the dormant polymeric alkoxyamine and the polymeric radical and nitroxide, respectively, lies far on the left side. Hence, a low concentration of radicals is ensured during the entire polymerization process. Consequently, irreversible terminations via polymer radical dimerization and disproportionation processes are suppressed due to low radical concentrations [4a].In NMP, alkoxyamines are applied as initiators/regulators [1]. In the early work, TEMPO was used as nitroxide component to regulate radical polymerization of styrene and styrene derivatives. Unfortunately, controlled NMP of acrylates (= prop-2-enoates) could not be achieved with TEMPO as a regulator [1c]. However, in the meantime, a few reports on successful acrylate polymerizations in the presence of cyclic and noncyclic alkoxyamines have appeared [5 -8]. Hawker and Braslau showed that readily pre-