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Asymmetric Diels-Alder reaction is one step in the biosynthesis of the statin lovastatin. [60] The retro-Diels–Alder reaction is used in the industrial production of cyclopentadiene. Cyclopentadiene is a precursor to various norbornenes, which are common monomers. The Diels–Alder reaction is also employed in the production of vitamin B6.
For example, an analog for the Diels-Alder reaction is the quadricyclane-DMAD reaction: In the (i+j+...) cycloaddition notation i and j refer to the number of atoms involved in the cycloaddition. In this notation, a Diels-Alder reaction is a (4+2)cycloaddition and a 1,3-dipolar addition such as the first step in ozonolysis is a (3+2)cycloaddition.
The Diels-Alder reaction, also known as cycloaddition, combines a conjugated diene and an alkene to form cycloalkene. This is a concerted process, with bonds forming and breaking simultaneously. This is a concerted process, with bonds forming and breaking simultaneously.
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The synchronous 6π-electron Diels-Alder reaction is a [π 4 s + π 2 s]-cycloaddition (i.e. suprafacial with respect to both components), as exemplified by the reaction to the right. The Diels-Alder reaction is suprafacial with respect to both components. Thus as the total number of antarafacial components is 0, which is even, the reaction is ...
The activated double bond in oxanobornadiene makes a triazoline intermediate that subsequently spontaneously undergoes a retro Diels-alder reaction to release furan and give 1,2,3- or 1,4,5-triazoles. Even though this reaction is slow, it is useful because oxabornodiene is relatively simple to synthesize.
Because C−C bond energy is so high (377 kJ/mol), [18] this reaction is not observed under laboratory conditions. More common examples of cracking reactions involve retro-Diels–Alder reactions. Illustrative is the thermal cracking of dicyclopentadiene to produce cyclopentadiene.
Oxazolidinone auxiliaries, popularized by David A. Evans, have been applied to many stereoselective transformations, including aldol reactions, [19] alkylation reactions, [20] and Diels-Alder reactions. [21] [22] The oxazolidinones are substituted at the 4 and 5 positions. Through steric hindrance, the substituents direct the direction of ...