Bioinspired Synthesis of Pygmaeocins and Related Rearranged Abietane Diterpenes: Synthesis of Viridoquinone
作者:Mustapha Ait El Had、Juan J. Guardia、Jose M. Ramos、Moha Taourirte、Rachid Chahboun、Enrique Alvarez-Manzaneda
DOI:10.1021/acs.orglett.8b02395
日期:2018.9.21
A bioinspired synthesis of rearranged abietane diterpenes, related to pygmaeocins, is described. In this process, the key step is the 1,2-migration of the C-20 angular methyl to the C-5 position of the abietane skeleton, which occurs when a C6–C7 unsaturated dehydroabietane derivative is treated with SeO2 in dioxane under reflux (19 examples for this rearrangement are described). Utilizing this reaction
The first enantioselective total syntheses of pygmaeocinsB and C have been accomplished using an efficient and highly diastereoselective intramolecular Heck cyclization for the construction of a quaternary stereogenic center and the functionalized A-ring of the natural products as the key step.