Search results
Results from the WOW.Com Content Network
The Buchner ring expansion is a two-step organic C-C bond forming reaction used to access 7-membered rings. The first step involves formation of a carbene from ethyl diazoacetate, which cyclopropanates an aromatic ring. The ring expansion occurs in the second step, with an electrocyclic reaction opening the cyclopropane ring to form the 7 ...
Ethyl diazoacetate (N=N=CHC(O)OC 2 H 5) is a diazo compound and a reagent in organic chemistry. It was discovered by Theodor Curtius in 1883. [4] The compound can be prepared by reaction of the ethyl ester of glycine with sodium nitrite and sodium acetate in water. As a carbene precursor, it is used in the cyclopropanation of alkenes.
In organic chemistry, the Roskamp reaction is a name reaction describing the reaction between α-diazoesters (such as ethyl diazoacetate) and aldehydes to form β-ketoesters, often utilizing various Lewis acids (such as BF 3, SnCl 2, and GeCl 2) as catalysts. [1] [2] [3] The reaction is notable for its mild reaction conditions and selectivity.
The Buchner–Curtius–Schlotterbeck reaction is the reaction of aldehydes or ketones with aliphatic diazoalkanes to form homologated ketones. [1] It was first described by Eduard Buchner and Theodor Curtius in 1885 [ 2 ] and later by Fritz Schlotterbeck in 1907. [ 3 ]
This reaction is also called the Regitz diazo transfer. [7] Examples are the synthesis of tert-butyl diazoacetate [8] and diazomalonate. [9] Methyl phenyldiazoacetate is generated in this way by treating methyl phenylacetate with p-acetamidobenzenesulfonyl azide in the presence of base. [10] [11]
A diazo cross-coupling reaction has also been reported between ethyl diazoacetate and methyl phenyldiazoacetate using the rhodium catalyst [Rh 2 (OPiv) 4]. [ 5 ] A direct metal carbene dimerization has been used in the synthesis of novel Polyalkynylethenes [ 6 ]
The Diels-Alder reaction is perhaps the most important and commonly taught cycloaddition reaction. Formally it is a [4+2] cycloaddition reaction and exists in a huge range of forms, including the inverse electron-demand Diels–Alder reaction, hexadehydro Diels–Alder reaction and the related alkyne trimerisation.
Enone–alkene cycloadditions often suffer from side reactions, e.g. those associated with the diradical intermediate. These side reactions can often be minimized by a judicious choice of reaction conditions. Dissolved oxygen is avoided since it is photoreactive. A variety of solvents can be used.