Total Synthesis of Guanacastepene A: A Route to Enantiomeric Control
作者:Mihirbaran Mandal、Heedong Yun、Gregory B. Dudley、Songnian Lin、Derek S. Tan、Samuel J. Danishefsky
DOI:10.1021/jo051470k
日期:2005.12.1
ketone (see compound 41). Actually, cyclization was best accomplished when the terminal double bond of 41 was first converted to an epoxide. Further issues related to the stereochemistry at C5 and, rather surprisingly, the propensity for β-face acetoxylation at C13. Crystallographic verification of the assigned β-stereochemistry at C13 is provided. Finally, a route to opticallyactive material is provided
作者:Doleshwar Niroula、Liam P. Hallada、Snezna Rogelj、Rodolfo Tello-Aburto
DOI:10.1016/j.tet.2016.12.013
日期:2017.1
A total synthesis of the cytotoxic terpenoid hortonone C was accomplished and its absolute stereochemistry confirmed. Intermediate (+)-4 was synthesized using either an asymmetric conjugate addition strategy, or by elaboration of the Hajos-Parrish ketone. Reduction of (+)-4 under dissolving-metal conditions and trapping the enolate intermediate served to control the cis-stereochemistry at the ring