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The hydrogen atoms in cyclopentadiene undergo rapid [1,5]-sigmatropic shifts. The hydride shift is, however, sufficiently slow at 0 °C to allow alkylated derivatives to be manipulated selectively. [10] Diene-selective Diels–Alder reaction in Corey's total synthesis of prostaglandin F2α
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.
The aza Diels-Alder reaction may occur either by a concerted or stepwise process. The lowest-energy transition state for the concerted process places the imine lone pair (or coordinated Lewis acid) in an exo position. Thus, (E) imines, in which the lone pair and larger imine carbon substituent are cis, tend to give exo products. [2]
As with cyclopentadiene, methylcyclopentadiene is prepared by thermal cracking of its Diels–Alder dimer, followed by distillation for removal of cyclopentadiene, a common impurity. [ 1 ] Methylcyclopentadienyl anion
The reaction is reversible and at room temperature cyclopentadiene dimerizes over the course of hours to re-form dicyclopentadiene. Cyclopentadiene is a useful diene in Diels–Alder reactions as well as a precursor to metallocenes in organometallic chemistry. It is not available commercially as the monomer, due to the rapid formation of ...
The inverse electron demand Diels–Alder reaction, or DA INV or IEDDA [1] is an organic chemical reaction, in which two new chemical bonds and a six-membered ring are formed. It is related to the Diels–Alder reaction , but unlike the Diels–Alder (or DA) reaction, the DA INV is a cycloaddition between an electron-rich dienophile and an ...
Hexachlorocyclopentadiene is prepared by chlorination of cyclopentadiene to give 1,1,2,3,4,5-octachlorocyclopentane, which in a second step undergoes dehydrochlorination: [3] The first procedure uses alkaline hypochlorite and after fractional distillation has a yield of about 75%, the other 25% consists of lower chlorinated cyclopentadienes. [4]
Dieldrin can be formed from the Diels-Alder reaction of hexachloro-1,3-cyclopentadiene with norbornadiene followed by epoxidation of the addition product with a peroxy acid such as peracetic acid. [6] Synthesis of dieldrin. Technical dieldrin contains 5-15% related polychloroepoxyoctahydro- dimethanonaphthalenes.