The central β-lactam ring of the title compound, C(23)H(21)NO(3), is almost planar (r.m.s. deviation = 0.032Å). The meth-oxy-benzene ring is almost coplanar with the β-lactam ring [dihedral angle = 1.87 (11)°], whereas the tolyl ring is almost normal to it [75.73 (12)°]. The dihedral angle between the β-lactam ring and the O-bonded phenyl ring is 51.95 (12)°. An intra-molecular C-H⋯O inter-acti...

A synchrotron radiation (SR) facility typically consists of an injector, a storage ring, and SR beamlines. The latter two features are unique to SR facilities, when compared to other types of accelerator facilities. The SR facilities have the characteristics of low injection beam power, but high stored beam power. The storage ring is generally above ground with people occupying the experimental...

The title compound, C24H33NO4·H2O, the reaction product of de-acetyl-cinobufagin with ammonium acetate, consists of three cyclo-hexane rings (A, B and C), one five-membered ring (D), one six-membered lactone ring (E) and an epoxide ring (F). The stereochemistry of the ring junctures are A/B cis, B/C trans, C/D cis and D/F cis. Cyclo-hexane rings A, B and C have normal chair conformations. The f...

In this short note, we investigate the existence of orbifold Kähler–Einstein metrics on toric varieties. particular, show that every Q $\mathbb {Q}$ -factorial normal projective variety allows an metric. Moreover, characterize K $K$ -stability pairs Picard number one in terms log Cox ring and universal cover.

The title compound, C24H30O7, is a diterpenoid isolated from the seeds of Caesalpinia minax. It consists of two cyclo-hexane rings (A and B), one unsaturated six-membered ring (C) and one furan ring (D). The stereochemistry of the ring junctures is A/B trans and B/C trans. Rings A and B have normal chair conformations while C adopts a twisted half-chair conformation due to fusion to the furan r...

In the title compound, C19H13BrN2O5, the spiro furan ring is almost planar with a maximum deviation of 0.034 (2) Å. The indole unit and the furan ring are normal to each other, making a dihedral angle of 87.82 (8) °. The mol-ecular structure is stabilized by an intra-molecular N-H⋯O hydrogen bond, which generates an S(6) ring motif. In the crystal, mol-ecules are linked via pairs of N-H⋯O hydro...

Simple theoretical calculations have suggested that small body impacts onto Pluto's newly discovered small satellites, Nix and Hydra, are capable of generating time-variable rings or dust sheets in the Pluto system. Using HST/ACS data obtained on 2006 February 15 and 2006 March 2, we find no observational evidence for such a ring system and present the first constraints on the present-day I/F a...