19β,28-Epoxy-18α-olean-3β-ol
نویسندگان
چکیده
منابع مشابه
19β,28-Epoxy-18α-olean-3β-ol
The title triterpene, C(30)H(50)O(2), is an 18α-oleanane derivative prepared by the Wagner-Meerwein rearrangement of betulin with Bi(OTf)(3).xH(2)O (OTF is trifluoromethanesulfonate). There are two symmetry-independent mol-ecules in the asymmetric unit that show no significant differences concerning bond lengths and angles. The conformation of the six-membered rings is close to a chair form, wh...
متن کامل3-Oxo-18α-olean-28,13β-olide
The title terpene, C(30)H(46)O(3), is a 28,13β-lactone of oleanolic acid prepared with bis-muth trifluoro-methane-sulfonate (OTf), Bi(OTf)(3)·xH(2)O. All rings are trans-fused. The X-ray study shows the inversion of the orientation of 18-H in the lactonization reaction. A quantum chemical ab-initio Roothaan Hartree-Fock calculation of the equilibrium geometry of the isolated mol-ecule gives val...
متن کامل(E)-17β,19-Epoxymethano-17,23,24-tridemethyl-4-nor-5β,18α-olean-3-one oxime
In the penta-cyclic triterpenoide skeleton of the title mol-ecule, C(27)H(43)NO(2) [systematic name: (3E,3aS,5aR,5bR,7aR,11R,11aR,11bR,13aR,13bR)-5a,5b,10,10,13b-penta-methyl-icosa-hydro-1H-11,7a-(epoxy-methano)cyclo-penta-[a]chrysen-3-one oxime], the five-membered ring A has an envelope conformation, while the six-membered rings B-E adopt chair conformations. Rings A and B are cis-fused. The h...
متن کاملFirst Total Synthesis of Ergosta-5,8-dien-3β-ol
The first total synthesis of ergosta-5,8-dien-3β-ol, an uncommon sterol previously isolated from an alga and several microorganisms, has been developed. For the first time, a full set of spectroscopic data of this sterol is presented.
متن کامل2′-Methylpyrazolo[4′,3′:16,17]androst-5-en-3β-ol
In the title compound, C(21)H(30)N(2)O, there are five fused rings. The A and C rings adopt chair conformations, ring B adopts an 8β,9α-half-chair conformation and ring D adopts a 14α-envelope conformation. The pyrazole ring is planar. Inter-molecular O-H⋯N hydrogen bonds [H⋯N = 1.88 (5) Å] help to stabilize the crystal structure. The absolute structure was deduced from those of the starting ma...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Acta Crystallographica Section E Structure Reports Online
سال: 2009
ISSN: 1600-5368
DOI: 10.1107/s1600536809030311