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The Diels–Alder reaction was one step in an early preparation of the steroids cortisone and cholesterol. [75] The reaction involved the addition of butadiene to a quinone. Diels-Alder in the total synthesis of cortisone by R. B. Woodward. Diels–Alder reactions were used in the original synthesis of prostaglandins F2α and E2. [76]
The pivotal intermediate leads to a straightforward conversion to the Diels-Alder structural goal, which provides the carbon framework for the functionalized cyclopentane ring. Later Corey developed an asymmetric Diels-Alder reaction employing a chiral oxazoborolidine, greatly simplifying the synthetic route to the prostaglandins.
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.
The retro-Diels–Alder reaction (rDA reaction) is the reverse of the Diels–Alder (DA) reaction, a [4+2] cycloelimination. It involves the formation of a diene and dienophile from a cyclohexene . It can be accomplished spontaneously with heat, or with acid or base mediation.
Otto Paul Hermann Diels (German pronunciation: [ˈɔto ˈdiːls] ⓘ; 23 January 1876 – 7 March 1954) was a German chemist. His most notable work was done with Kurt Alder on the Diels–Alder reaction, a method for cyclohexene synthesis. [1] The pair was awarded the Nobel Prize in Chemistry in 1950 for their work.
Cyclopentadiene is a highly reactive diene in the Diels–Alder reaction because minimal distortion of the diene is required to achieve the envelope geometry of the transition state compared to other dienes. [11] Famously, cyclopentadiene dimerizes. The conversion occurs in hours at room temperature, but the monomer can be stored for days at ...
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 ...
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 ...