The pagodane route to dodecahedranes: highly functionalized, saturated, and unsaturated pentagonal dodecahedranes via aldol-type cyclizations
作者:Johann Peter Melder、Rolf Pinkos、Hans Fritz、Juergen Woerth、Horst Prinzbach
DOI:10.1021/ja00052a019
日期:1992.12
Pentagonal dodecahedranes with four, six, and eight skeletal positions being functionalized are made available from dimethyl 14,19-dioxopagodane-4-syn,9-syn-dicarboxylate 7 as a common precursor. Key steps are the installation of the two carbonyl functions of 7 into the expeditiously available pagodane 4-syn,7-syn-diester, the 2σ→2π pagodane isomerization into a respective bissecododecahedradiene,
The pagodane route to dodecahedranes-functional group manipulations on the dodecahedrane sphere
作者:Klaus Scheumann、Fabian Wahl、Horst Prinzbach
DOI:10.1016/s0040-4039(00)92325-6
日期:1992.1
Reductive and halogenative Barton decar☐ylation methodologies provide an expeditious access to variously 1,6-di- and 1,6,11,16-tetrasubstituted pentagonal dodecahedranes. Vicinal CO2R and Cl substituents cause increasing competition in the radical transfer step.
With the use of four- to eight-fold functionalized dodecahedranes (1-3), opportunities to arrive at highly strained dodecahedranes with two to four pairs of vicinal, eclipsed bromine substituents through front-side substitution and addition reactions have been explored. In standard processes, the interception of beta-OCH(3) radical/cationic intermediates was not problematic (9-12, 37, 50). The interception