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.
New 20(10?5)abeo-Diterpenoids fromPygmaeopremna herbacea
作者:Qingchang Meng、Manfred Hesse
DOI:10.1002/hlca.19900730225
日期:1990.3.14
Two new 20(105)abeo-abietune diterpenoids, pygmaeooins B (1) and C (2), have been isolated from the roots of Pygmaeopremnaherbacea (Verbenaceae). Their structures were elucidated on the basis of spectroscopic data, and chemically, both compounds were correlated with each other. The absolute configurations were assigned tentatively on the basis of biogenetic pathway.