Jiquilpane hydrocarbon skeleton generated by two successive Wagner-Meerwein rearrangements of longipinane derivatives.
The molecular rearrangement of (1R,3S,4S,5S,7S,8R,9S,10R,11R)-7,8,9-triacetyloxylongipinan-1-ol (4) under acidic conditions afforded (1S,4R,5R,7S,8R,9S,10S)-7,8,9-triacetyloxyuruap-3(12)-ene (5), while 6, the C(3)-stereoisomer of 4, after two consecutive Wagner-Meerwein rearrangements followed by two 1,2-hydride migrations, afforded (4R,5R,7S,8S,9S,10S,11S)-7,8,9-triacetyloxyjiquilp-3(12)-ene (7), which possesses a new hydrocarbon skeleton. The structures of the new substances were elucidated by 1D and 2D NMR data in combination with X-ray diffraction analyses of the uruapane, longipinane, and jiquilpane derivatives 5, 6, and 14, respectively. Molecular modeling at the ab initio level was used to study the reaction mechanisms, while deuterium labeling was employed to confirm the C-C bond migrations and the hydride shifts.
Román
Luisa U
LU
Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Apartado 137, Morelia, Michoacán, 58000 Mexico.
Cerda-García-Rojas
Carlos M
CM
Guzmán
Ramón
R
Armenta
Concepción
C
Hernández
Juan D
JD
Joseph-Nathan
Pedro
P
D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D012717:Sesquiterpenes / Q000737:chemistry*; D013237:Stereoisomerism; D014961:X-Ray Diffraction
D012717:Sesquiterpenes; C410907:longipinene