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An anionic organoaluminium compound with a carbon–aluminium bond at an alkene carbon.

An ether with oxygen directly attached to a vinylic carbon, $\mathrm{R}-\mathrm{O}-\mathrm{CH}=\mathrm{C}{\mathrm{H}}_2$ in the simplest terminal example. oxygen resonance donation strongly differentiates the two alkene carbon shifts.

The group $\mathrm{C}{\mathrm{H}}_2=\mathrm{CH}-$, attached through an alkene carbon. It differs from an allyl group, whose attachment includes an intervening methylene.

A grignard reagent in which magnesium is attached directly to an alkenyl carbon, $\mathrm{RCH}=\mathrm{CHMgX}$. Addition to a carbonyl compound can form an allylic alcohol while retaining the geometry of the pre-existing alkene.

Aldol-type carbonyl addition at a more remote carbon of a conjugated enolate.

An enolate whose nucleophilic carbon is conjugated to a carbonyl through an additional unsaturated unit.

Reaction of a phosphorus ylide with a carbonyl compound to form an alkene. The carbonyl carbon and ylidic carbon become the two alkene atoms; the oxygen is transferred to phosphorus.