Backbone rearrangements of methyl (-)-kaur-9(11)-en-19-oate and its epoxide: structures of two diterpenes of a new skeletal type
作者:Tatsuhiko Nakano、A.C. Spinelli、A. Martín、A. Usubillaga、Andrew T. McPhail、Kay D. Onan
DOI:10.1016/s0040-4039(00)87690-x
日期:1982.1
cleavage of the epoxide () of methyl (-)-kaur-9(11)-en-19-oate () with boron trifluoride-ether in benzene and in acetic anhydride yielded () and (), respectively. On epoxidation with -chloroperbenzoic acid in the presence of -nitrosomethyl urea, () suffered a backbone rearrangement to form ().
Rearrangements of methyl 9β-hydroxy-11-oxo-(−)-kauran-19-oate to diterpene skeletons with new ring systems
作者:Tatsuhiko Nakano、Maria Aracelis Maillo、Alfredo Usubillaga、Andrew T. McPhail、Donald R. McPhail
DOI:10.1016/0040-4039(91)80560-s
日期:1991.12
etherate-acetic anydride-acetic acid, the 9β-hydroxy-11-oxo derivative 1c of methyl(−)-kaur-9(11)-en-19-oate did not form a pinacolic type of rearrangement product (B-homo derivative), but instead it yielded compounds 2 and 3. With boron trifluoride etherate-acetic anhydride, however, compound 1c underwent a profound backbone rearrangement leading to the formation of compound 4a.