(2E,4E)-Ethyl 5-(2,4-di-chloro-phenyl-sulfon-yl)penta-2,4-dienoate.

In the title compound, C13H12Cl2O4S, both C=C double bonds adopt an E conformation. The S atom has a distorted tetra-hedral geometry with bond angles ranging from 103.03 (12) to 118.

Ethyl (2E,4E)-5-(3-bromo-phenyl-sulfon-yl)penta-2,4-dienoate.

In the title compound, C13H13BrO4S, both C=C double bonds adopt an E conformation. The S atom has a distorted tetra-hedral geometry with bond angles ranging from 102.17 (13) to 119.

3-Methyl-2-vinyl-pyridinium phosphate.

In the title salt, C8H10N(+)·H2PO4 (-), the cation is essentially planar (r.m.s.

(1'S,12'R,13'S,17'S)-15',15'-Dimethyl-1,2-dihydro-11',14',16',18'-tetra-oxa-7'-aza-spiro-[indole-3,8'-penta-cyclo-[10.6.0.0(2,9).0(3,7).0(13,17)]octa-deca-ne]-2,10'-dione.

In the title compound, C22H24N2O6, the indole ring has a twist conformation and the tetra-hydro-2H-pyran-2-one ring a half-chair conformation. One of the pyrrolidine rings adopts an envelope conformation on the N atom, while the other has a twist conformation; the 'butterfly' angle between their mean planes is 62.98 (11)°.