For 10 points, identify this class of compounds that can be either cis or trans and are characterized by carbon-carbon double bonds.
A common method of reducing these compounds involves using a catalyst containing 3 P-Ph-3 groups and one chlorine atom bound to ruthenium, a method which has largely been replaced by Crabtree's catalyst. Reacting them with carbenes is a common method of producing cyclopropanes. A series of these compounds alternating on a long side chain serves as a chromophore in retinal. When they are reacted with osmium tetraoxide, diols are formed. Acid halides add to these compounds such that the halide adds to the more substituted carbon, a rule named for Markovnikov. For 10 points, identify this class of compounds that can be either cis or trans and are characterized by carbon-carbon double bonds.
A common method of reducing these compounds involves using a catalyst containing 3 P-Ph-3 groups and one chlorine atom bound to ruthenium, a method which has largely been replaced by Crabtree's catalyst.
{alkenes} [or {olefins}]