Chihui An1, Jon A Jurica, Shawn P Walsh, Adam T Hoye, Amos B Smith. 1. Department of Chemistry, Laboratory for Research on the Structure of Matter and Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Abstract
A unified synthetic strategy to access (+)-irciniastatin A (a.k.a. psymberin) and (-)-irciniastatin B, two cytotoxic secondary metabolites, has been achieved. Highlights of the convergent strategy comprise a boron-mediated aldol union to set the C(15)-C(17) syn-syn triad, reagent control to set the four stereocenters of the tetrahydropyran core, and a late-stage Curtius rearrangement to install the acid-sensitive stereogenic N,O-aminal. Having achieved the total synthesis of (+)-irciniastatin A, we devised an improved synthetic route to the tetrahydropyran core (13 steps) compared to the first-generation synthesis (22 steps). Construction of the structurally similar (-)-irciniastatin B was then achieved via modification of a late-stage (-)-irciniastatin A intermediate to implement a chemoselective deprotection/oxidation sequence to access the requisite oxidation state at C(11) of the tetrahydropyran core. Of particular significance, the unified strategy will permit late-stage diversification for analogue development, designed to explore the biological role of substitution at the C(11) position of these highly potent tumor cell growth inhibitory molecules.
A unified synthetic strategy to access n class="Chemical">(+)-irciniastatin A (a.k.a. psymberin) and (-)-irciniastatin B, two cytotoxic secondary metabolites, has been achieved. Highlights of the convergent strategy comprise a boron-mediated aldol union to set the C(15)-C(17) syn-syn triad, reagent control to set the four stereocenters of the tetrahydropyran core, and a late-stage Curtius rearrangement to install the acid-sensitive stereogenic N,O-aminal. Having achieved the total synthesis of (+)-irciniastatin A, we devised an improved synthetic route to the tetrahydropyran core (13 steps) compared to the first-generation synthesis (22 steps). Construction of the structurally similar (-)-irciniastatin B was then achieved via modification of a late-stage (-)-irciniastatin A intermediate to implement a chemoselective deprotection/oxidation sequence to access the requisite oxidation state at C(11) of the tetrahydropyran core. Of particular significance, the unified strategy will permit late-stage diversification for analogue development, designed to explore the biological role of substitution at the C(11) position of these highly potent tumor cell growth inhibitory molecules.
Authors: George R Pettit; Jun-Ping Xu; Jean-Charles Chapuis; Robin K Pettit; Larry P Tackett; Dennis L Doubek; John N A Hooper; Jean M Schmidt Journal: J Med Chem Date: 2004-02-26 Impact factor: 7.446
Authors: Shuangyi Wan; Fanghui Wu; Jason C Rech; Michael E Green; Raghavan Balachandran; W Seth Horne; Billy W Day; Paul E Floreancig Journal: J Am Chem Soc Date: 2011-09-22 Impact factor: 15.419
Authors: Cheng-Yang Wu; Yu Feng; Eduardo R Cardenas; Noelle Williams; Paul E Floreancig; Jef K De Brabander; Michael G Roth Journal: J Am Chem Soc Date: 2012-11-13 Impact factor: 15.419