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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.
It is commonly thought to be named after the Nobel Laureate Eduard Buchner (without umlaut), but it is actually named after the industrial chemist Ernst Büchner. [2] A Büchner funnel fitted with Sintered Disc made of Boro 3.3 Glass. Diagram of filtration set-up using a Büchner flask
A generalized mechanism of the Buchner ring expansion. A common method for expanding a ring involves opening cyclopropane-containing bicyclic intermediate. The strategy can start with a Simmons-Smith-like cyclopropanation of a cyclic alkene. [3] A related cyclopropane-based ring expansion is the Buchner ring expansion.
cylindrical type graduated and ungraduated with cone and socket; with pressure equalizing tube; pear shaped, graduated and ungraduated; Pressure-equalizing dropping funnels have an additional narrow-bore glass tube from the bulb of the funnel, to the ground glass joint around the stem.
Diagram of the vacuum filtration apparatus. By flowing through the aspirator, water will suck out the air contained in the vacuum flask and the Büchner flask.There is therefore a difference in pressure between the exterior and the interior of the flasks : the contents of the Büchner funnel are sucked towards the vacuum flask.
The short tube and hose barb effectively act as an adapter over which the end of a thick-walled flexible hose (tubing) can be fitted to form a connection to the flask.
Initial steps in the Buchner–Curtius–Schlotterbeck reaction mechanism. The reaction is then completed either by the reformation of the carbonyl through an 1,2-rearrangement or by the formation of the epoxide. There are two possible carbonyl products: one formed by migration of R 1 (4) and the other by migration of R 2 (5). The relative ...
Eduard Buchner (German: [ˈeːduaʁt ˈbuːxnɐ] ⓘ; 20 May 1860 – 13 August 1917) was a German chemist and zymologist, awarded the 1907 Nobel Prize in Chemistry for his work on fermentation. [ 1 ]