0 any gas in a group that contains carbon and hydrogen atoms, with the carbon atoms joined together in a double bond:
Ethene and propene are alkenes.
1 any of a group of substances that contain only the elements carbon and hydrogen, which are held together by a chemical bond in which two atoms share two pairs of electrons
The data indicated that at least one alkene was present.
Paraffins are formed simultaneously with the alkene series but no acetylenic hydrocarbons have been detected.
All reactions proceed via an initial addition of the radical to alkenes, alkynes and aromatic species.
The relative proportions of alkenes were higher in this group (around 28 % versus 18 % of the total hydrocarbons).
The chemoselective ruthenium-catalysed olefin metathesis reaction was used to 'staple' together the two alkene tethers to provide peptides that maintain helical structure, but with enhanced stability.
Methane, a series of about 20 different alkenes with single and conjugated double bonds have been detected.
The epoxides are prepared by oxidation with hydrogen peroxide of the alkene.
The carbonyl group draws electrons away from the alkene, and the alkene group is, therefore, deactivated towards an electrophile, such as bromine or hydrochloric acid.
