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The Wittig reaction involves reaction of an aldehyde or ketone with a Wittig reagent (or phosphorane) of the type Ph 3 P=CHR to produce an alkene and Ph 3 P=O. The Wittig reagent is itself prepared easily from triphenylphosphine and an alkyl halide.
In organic chemistry, alkylidene is a general term for divalent functional groups of the form R 2 C=, where each R is an alkane or hydrogen. [1] They can be considered the functional group corresponding to mono- or disubstituted divalent carbenes (known as alkylidenes), [2] or as the result of removing two hydrogen atoms from the same carbon atom in an alkane.
In organic chemistry, syn-and anti-addition are different ways in which substituent molecules can be added to an alkene (R 2 C=CR 2) or alkyne (RC≡CR).The concepts of syn and anti addition are used to characterize the different reactions of organic chemistry by reflecting the stereochemistry of the products in a reaction.
The reverse reaction of RCM, ring-opening metathesis, can likewise be favored by a large excess of an alpha-olefin, often styrene. Ring-opening metathesis usually involves a strained alkene (often a norbornene) and the release of ring strain drives the reaction. Ring-closing metathesis, conversely, usually involves the formation of a five- or ...
The reverse reaction, the de-insertion of CO and alkenes, are of fundamental significance in many catalytic cycles as well. Widely employed applications of migratory insertion of carbonyl groups are hydroformylation and the carbonylative production of acetic acid. The former converts alkenes, hydrogen, and carbon monoxide into aldehydes.
The patent describes the reaction of the alkenes with excess maleic anhydride at 200 °C in an autoclave. The excess alkene is removed by distillation in vacuo, the resulting alkenyl succinic anhydride hydrolyzed with dilute sodium hydroxide solution and the disodium salt reacted with an acid to achieve an alkenebutanedioic acid.
The alkene donates electron density into a π-acid metal d-orbital from a π-symmetry bonding orbital between the carbon atoms. The metal donates electrons back from a (different) filled d-orbital into the empty π * antibonding orbital. Both of these effects tend to reduce the carbon-carbon bond order, leading to an elongated C−C distance ...
There are two types of alpha-olefins, branched and linear (or normal). The chemical properties of branched alpha-olefins with a branch at either the second (vinylidene) or the third carbon number are significantly different from the properties of linear alpha-olefins and those with branches on the fourth carbon number and further from the start of the chain.