title: Eremophilane esters of Robinsonecio gerberifolius and their rearranged products. Study of the coupling constants (2)J(H, H), (3)J(H, H) and (4)J(H, H).
abstract: In the course of the basic hydrolysis of four eremophilane esters isolated from Robinsonecio gerberifolius, some rearrangements, eliminations, and additions occurred. Five compounds were obtained, three of them not previously described. Additionally, a new sesquiterpene was produced by autooxidation of compound 1. The (1)H and (13)C NMR spectra of these compounds were completely assigned by utilization of HMQC, HMBC, COSY, DEPT, and NOESY techniques. The long-range coupling constants of the peroxide 10 are reported, and all its coupling constants (2)J(H, H), (3)J(H, H), and (4)J(H, H) are calculated at the B3LYP/6-31G(d,p) level of theory. Their magnitude is explained in terms of electronic delocalization and the additivity of stereoelectronic effects.
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Coyoacán 04510, México D.F, México.
authors.forename: Amira
authors.initials: A
authors.lastname: Arciniegas
authors.forename: Ana-L
authors.initials: AL
authors.lastname: Pérez-Castorena
authors.forename: Gabriel
authors.initials: G
authors.lastname: Cuevas
authors.forename: Federico
authors.initials: F
authors.lastname: Del Río-Portilla
authors.forename: Alfonso Romo
authors.initials: AR
authors.lastname: de Vivar
mesh_terms: D019659:Asteraceae / Q000737:chemistry*; D004952:Esters / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry* / Q000145:classification; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes
chemical_list: D004952:Esters; D009281:Naphthalenes; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes; C018286:eremophilane compounds