Assignment of Absolute Configuration to SCH 351448 via Total Synthesis
作者:Lael L. Cheung、Shinji Marumoto、Christopher D. Anderson、Scott D. Rychnovsky
DOI:10.1021/ol8011474
日期:2008.7.17
The synthesis and absoluteconfiguration of SCH 351448, an interesting ionophoric natural product, are reported herein. Mukaiyama aldol-Prins and segment-coupling Prins reactions were employed to construct the constituent tetrahydropyrans of SCH 351448. Efforts to assemble the C2-symmetric core of the natural product by a templated olefin metathesis strategy are described; however, a stepwise fragment
Total Syntheses of 2,2‘-<i>epi</i>-Cytoskyrin A, Rugulosin, and the Alleged Structure of Rugulin
作者:K. C. Nicolaou、Yee Hwee Lim、Jared L. Piper、Charles D. Papageorgiou
DOI:10.1021/ja0685708
日期:2007.4.1
The total syntheses of 2,2'-epi-cytoskyrin A, rugulosin, and the alleged structure of rugulin are described. These naturally occurring bisanthraquinones and their relatives are characterized by novel molecular architectures at the core, at which lies a more or less complete, cage-like structural motif termed "skyrane". The strategies developed for their total synthesis feature a cascade sequence called the "cytoskyrin cascade" and deliver these molecules in short order and in a stereoselective manner.
Synthetic Versatility in C–H Oxidation: A Rapid Approach to Differentiated Diols and Pyrans from Simple Olefins
作者:Paul E. Gormisky、M. Christina White
DOI:10.1021/ja206013j
日期:2011.8.17
Conventionally, C-H oxidation reactions are used to install functional groups. The use of C-H oxidation to transform simple starting materials into highly versatile intermediates, which enable rapid access to a range of complex target structures, is a new area with tremendous potential in synthesis. Herein we report a Pd(II)/sulfoxide-catalyzed allylic C-H oxidation to form anti-1,4-dioxan-2-ones from homoallylic oxygenates. These versatile building blocks are rapidly elaborated to differentiated syn-1,2-diols, stereo-defined amino-polyols, and syn-pyrans, structures ubiquitous in medicinally important complex molecules found in Nature. We also demonstrate that a C-H oxidation approach to the synthesis of these motifs is orthogonal and complementary to other state-of-the-art methods.