Details

Autor(en) / Beteiligte

• Lapoot, Lloyd
• Jabeen, Shakeela
• Durantini, Andrés M.
• Greer, Alexander

Titel

Role of curvature in acridone for 1O2 oxidation of a natural product homoallylic alcohol: A novel iso‐hydroperoxide intermediate

Ist Teil von

• Photochemistry and photobiology, 2024-03, Vol.100 (2), p.455-464

Ort / Verlag

Lawrence: Blackwell Publishing Ltd

Erscheinungsjahr

2024

Link zum Volltext

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• A density functional theoretical (DFT) study is presented, implicating a 1O2 oxidation process to reach a dihydrobenzofuran from the reaction of the natural homoallylic alcohol, glycocitrine. Our results predict an interconversion between glycocitrine and an iso‐hydroperoxide intermediate [R(H)O+–O−] that provides a key path in the chemistry which then follows. Formations of allylic hydroperoxides are unlikely from a 1O2 ‘ene’ reaction. Instead, the dihydrobenzofuran arises by 1O2 oxidation facilitated by a 16° curvature of the glycocitrine ring imposed by a pyramidal N‐methyl group. This curvature facilitates the formation of the iso‐hydroperoxide, which is analogous to the iso species CH2I+–I− and CHI2+–I− formed by UV photolysis of CH2I2 and CHI3. The iso‐hydroperoxide is also structurally reminiscent of carbonyl oxides (R2C=O+–O−) formed in the reaction of carbenes and oxygen. Our DFT results point to intermolecular process, in which the iso‐hydroperoxide's fate relates to O‐transfer and H2O dehydration reactions for new insight into the biosynthesis of dihydrobenzofuran natural products. Strategies for improving 1O2 oxidation paths to dihydrobenzofurans are needed. A density functional theory study provides evidence that acridone curvature and phenol O–H···π bonding facilitate 1O2 oxidation of a prenyl side group to reach a dihydrobenzofuran. Mechanistic insight is provided for an iso‐hydroperoxide intermediate preceding the dihydrobenzofuran. Notably, our evidence for the iso‐hydroperoxide intermediate is reminiscent of other iso species, such as oxywater and iso‐iodoform in fields outside biosynthetic and 1O2 chemistry.