:Intramolecular Diels–Alder cycloaddition
In organic chemistry, an intramolecular Diels-Alder cycloaddition is a Diels–Alder reaction in which the diene and the dienophile are both part of the same molecule.{{cite book|author=Taber, D. F.|title=
Intramolecular Diels–Alder and Alder Ene Reactions|publisher=Springer|location=NY|year=1984}} The reaction leads to the formation of the cyclohexene-like structure as usual for a Diels–Alder reaction, but as part of a more complex fused or bridged cyclic ring system. This reaction can gives rise to various natural derivatives of decalin.{{cite journal |doi=10.1039/C4NP00031E|title=Natural products containing 'decalin' motif in microorganisms |year=2014 |last1=Li |first1=Gang |last2=Kusari |first2=Souvik |last3=Spiteller |first3=Michael |journal=Nat. Prod. Rep. |volume=31 |issue=9 |pages=1175–1201 |pmid=24984916 |doi-access=free }}
Reaction products
Because the two reacting groups are already attached, two basic modes of addition are possible in this reaction. Depending on whether the tether that links to the dienophile is attached to the end or the middle of the diene, fused or bridged polycyclic ring systems can be formed.M. Nantz, G. Zweifel. (2007) Modern Organic Synthesis an Introduction. W. H. Freeman, pp. 429–430, {{ISBN|0716772663}}.
The tether than attaches the two reacting groups also affects the geometry of the reaction. As a result of its conformational and other structural restrictions, the exo vs endo resultsP.Y Bruice (2007). Organic Chemistry. Pearson Education, Inc. are usually not based on the simple (intermolecular) Diels–Alder reaction effects.
Use in total synthesis
File:Corey 1978 gibberellic acid.png of gibberellic acid.{{cite journal|authorlink1=Elias James Corey|authorlink2=Rick L. Danheiser|last1=Corey|first1=E. J.|last2=Danheiser|first2=Rick L.|last3=Chandrasekaran|first3=Srinivasan|last4=Siret|first4=Patrice|last5=Keck|first5=Gary E.|last6=Gras|first6=Jean Louis|title=Stereospecific total synthesis of gibberellic acid. A key tricyclic intermediate|journal=Journal of the American Chemical Society|year=1978|volume=100|issue=25|pages=8031–8034|doi=10.1021/ja00493a055}}{{cite journal|last1=Corey|first1=E. J.|last2=Danheiser|first2=Rick L.|last3=Chandrasekaran|first3=Srinivasan|last4=Keck|first4=Gary E.|last5=Gopalan|first5=B.|last6=Larsen|first6=Samuel D.|last7=Siret|first7=Patrice|last8=Gras|first8=Jean Louis|title=Stereospecific total synthesis of gibberellic acid|journal=Journal of the American Chemical Society|year=1978|volume=100|issue=25|pages=8034–8036|doi=10.1021/ja00493a056}} Colour-coding: diene is blue, dienophile is red]]
Intramolecular Diels-Alder cycloaddition has been used in total synthesis. Through this reaction polycyclic compounds can be accessed with high stereoselectivity. The following potential drugs have been synthesized using the intramolecular Diels-Alder reaction: salvinorin A,{{cite journal|author1=A.C Burns |author2=C.J Forsyth |title= Intramolecular Diels-Alder/Tsuji Allylation Assembly of the Functionalized trans-Decalin of Salvinorin A|journal= Organic Letters|volume=10|issue=1 |year=2008|pages= 97–100|doi=10.1021/ol7024058|pmid=18062692}} himbacine,{{cite journal|author1=S. Chackalamannil |author2=R.J Davies |author3=Y. Wang |title=Total Synthesis of (+)- Himbacine and (+)-Himbeline|journal=J. Org. Chem.|volume= 64|year= 1999|pages= 1932–1940|doi=10.1021/jo981983+|pmid=11674285|issue=6|display-authors=etal}} and solanapyrone A.{{cite journal|author1=B. Lygo |author2=M. Bhatia |author3=J.W.B Cooke |author4=D.J Hirst |title= Synthesis of (+/-)- solanapyrones A and B|journal= Tetrahedron Letters|year= 2003|doi=10.1016/S0040-4039(03)00288-0|volume=44|issue=12|pages=2529}}
References
{{reflist}}
{{DEFAULTSORT:Intramolecular Diels-Alder cycloaddition}}