TY - DATA T1 - Total Synthesis of the Quinone Epoxide Dimer (+)-Torreyanic Acid:  Application of a Biomimetic Oxidation/Electrocyclization/Diels−Alder Dimerization Cascade1 PY - 2003/04/03 AU - Chaomin Li AU - Richard P. Johnson AU - John A. Porco UR - https://acs.figshare.com/articles/dataset/Total_Synthesis_of_the_Quinone_Epoxide_Dimer_-Torreyanic_Acid_Application_of_a_Biomimetic_Oxidation_Electrocyclization_Diels_Alder_Dimerization_Cascade_sup_1_sup_/3642231 DO - 10.1021/ja021396c.s002 L4 - https://ndownloader.figshare.com/files/5731041 KW - pyran quinone epoxide monomers KW - stereocontrol elements KW - Thermolysis experiments KW - diastereomeric 2 H KW - chiral quinone monoepoxide KW - biosynthetic relationship KW - Theoretical calculations KW - Diel KW - model dimer KW - synthesis KW - dimerization KW - hydroxyl group direction KW - torreyanic acid core structure KW - Total Synthesis KW - alternative transition states KW - pyran monomers KW - 2 H N2 - An asymmetric synthesis of the quinone epoxide dimer (+)-torreyanic acid (48) has been accomplished employing [4 + 2] dimerization of diastereomeric 2H-pyran monomers. Synthesis of the related monomeric natural product (+)-ambuic acid (2) has also been achieved which establishes the biosynthetic relationship between these two natural products. A tartrate-mediated nucleophilic epoxidation involving hydroxyl group direction facilitated the asymmetric synthesis of a key chiral quinone monoepoxide intermediate. Thermolysis experiments have also been conducted on a model dimer based on the torreyanic acid core structure and facile retro Diels−Alder reaction processes and equilibration of diastereomeric 2H-pyrans have been observed. Theoretical calculations of Diels−Alder transition states have been performed to evaluate alternative transition states for Diels−Alder dimerization of 2H-pyran quinone epoxide monomers and provide insight into the stereocontrol elements for these reactions. ER -