The enzyme SpnF, involved in the biosynthesis of spinosyn A, catalyzes a formal [4+2] cycloaddition of a 22-membered macrolactone, which may proceed as a concerted [4+2] Diels-Alder reaction or a stepwise [6+4] cycloaddition followed by a Cope rearrangement. Quantum mechanics/molecular mechanics (QM/MM) calculations combined with free energy simulations show that the Diels-Alder pathway is favo...

The first enantioselective total syntheses of prenylflavonoid Diels-Alder natural products (-)-kuwanon I, (+)-kuwanon J, (-)-brosimone A, and (-)-brosimone B have been accomplished from a common intermediate based on a concise synthetic strategy. Key elements of the synthesis include a biosynthesis-inspired asymmetric Diels-Alder cycloaddition mediated by a chiral ligand/boron Lewis acid, as we...

Nature's repertoire of biosynthetic transformations has recently been recognized to include the Diels-Alder cycloaddition reaction. Evidence now exists that there are enzymes that mediate the Diels-Alder reaction in secondary metabolic biosynthetic pathways. 2002 marked the 100th anniversary of Alder's birth and 75 years since the discovery of the Diels-Alder reaction. It would appear that livi...

Enyne alcohols can react as precursors of either dienes or dienophiles with different substrates after hydroxylation and isomerization by gold catalysis. As such, oxa-bridged tricyclo[5.2.2.02,6]-undec-8-ene-3,5-dione derivatives have been obtained by the Diels–Alder reaction and tetrahydro-1H-furo[3,4-c]pyran derivatives could be accessed by the hetero-Diels–Alder cycloaddition.

The first Diels-Alder cycloaddition of o-quinodimethane to SWNT has been performed under microwave irradiation.

We explore the potential of the Diels-Alder cycloaddition for the functional tagging of DNA strands. A deoxyuridine triphosphate derivative carrying a diene at position 5 of the pyrimidine base was synthesized using a two-step procedure. The derivative was efficiently accepted as substrate in enzymatic polymerization assays. Diene carrying strands underwent successful cycloaddition with maleimi...

A metal-free and formal [2 + 2 + 2] cycloaddition of triynes has emerged recently as a novel methodology for the synthesis of fused tricyclic compounds via an intramolecular cascade propargylic ene reaction, Diels-Alder cycloaddition and tautomerization. DFT calculations on three model systems reveal that the ene reaction with low distortion energy makes the metal-free strategy feasible and, as...

We demonstrate the applicability of sequential Diels-Alder and azide-alkyne [3 + 2] cycloaddition reactions (click chemistry) for the immobilization of carbohydrates and proteins onto a solid surface. An alpha,omega-poly(ethylene glycol) (PEG) linker carrying alkyne and cyclodiene terminal groups was synthesized and immobilized onto an N-(epsilon-maleimidocaproyl) (EMC)-functionalized glass sli...

Key words (±)-talatisamine - Diels–Alder reaction [2+2] photo-cycloaddition Lemieux–Johnson oxidation retro-aldol–aldol Wagner–Meerwein rearrangement aza-Prins

The methyl ether derivatives 2, 4 and 6 of the mulberry Diels-Alder adducts chalcomoracin (1) and mulberrofuran C (3) and kuwanon J (5) respectively have been synthesized by a thermal [4 + 2]-cycloaddition reaction between a chalcone and dehydroprenyl diene. A H-bonded ortho OH substituent on the chalcone was found to be essential for Diels-Alder reactivity. Density functional theory calculatio...