2α,8α-Diacetoxy-cis-himachalane
نویسندگان
چکیده
The title compound, C(19)H(32)O(4), was synthesized from γ-himachalene, wich was isolated from essential oils of Cedrus atlantica. The mol-ecule is built up from two fused six- and seven-membered rings. The six-membered ring has a screw-boat conformation, whereas the seven-membered ring displays a half-chair conformation; the dihedral angle between the mean planes of the rings is 61.99 (6)°.
منابع مشابه
Infinitely many local higher symmetries without recursion operator or master symmetry: integrability of the Foursov–Burgers system revisited
We consider the Burgers-type system studied by Foursov, w t = w xx + 8ww x + (2 − 4α)zz x , z t = (1 − 2α)z xx − 4αzw x + (4 − 8α)wz x − (4 + 8α)w 2 z + (−2 + 4α)z 3 , for which no recursion operator or master symmetry was known so far, and prove that this system admits infinitely many local higher symmetries that are constructed using a nonlocal two-term recursion relation rather than a recurs...
متن کاملAsymptotics of Instability Zones of the Hill Operator with a Two Term Potential
Let γ n denote the length of the n-th zone of instability of the Hill operator Ly = −y ′′ − [4tα cos 2x + 2α 2 cos 4x]y, where α = 0, and either both α, t are real, or both are pure imaginary numbers. For even n we prove: if t, n are fixed, then for α → 0 γ n = 8α n 2 n [(n − 1)!] 2 n/2 k=1 t 2 − (2k − 1) 2 (1 + O(α)) , and if α, t are fixed, then for n → ∞ γ n = 8|α/2| n [2 · 4 · · · (n − 2)] ...
متن کامل6β,15β-Diacetoxy-1β,7β,13α-trihydroxy-7α,20-epoxy-ent-kaur-16-ene
The title compound, C(24)H(34)O(8), a natural ent-kaurane diterpenoid, is composed of four rings with the expected cis and trans junctions. The crystal structure is stabilized by inter-molecular O-H⋯O hydrogen bonds. In addition, an intra-molecular O-H⋯O hydrogen bond occurs.
متن کاملEffects of conjugated linoleic acids on prostaglandin secretion by bovine endometrial epithelial cells in vitro.
OBJECTIVE To determine the effects of 2 conjugated linoleic acid (CLA) isomers (cis-9, trans-11 and trans-10, cis-12) on synthesis of prostaglandin (PG) E(2) and F(2α) and expression of prostaglandin H synthase-2 (PGHS-2) of adult and fetal bovine endometrial epithelial cells in vitro. SAMPLE Primary cultures of endometrial epithelial cells obtained from 4 adult cows and 4 fetal bovine carcas...
متن کاملHIF-2α Regulates NANOG Expression in Human Embryonic Stem Cells following Hypoxia and Reoxygenation through the Interaction with an Oct-Sox Cis Regulatory Element
Low O2 tension is beneficial for human embryonic stem cell (hESC) maintenance but the mechanism of regulation is unknown. HIF-2α was found to bind directly to predicted hypoxic response elements (HREs) in the proximal promoter of OCT4, NANOG and SOX2 only in hESCs cultured under hypoxia (5% O2). This binding induced an array of histone modifications associated with gene transcription while a he...
متن کامل