97838-50-1

Upstream product

• 14371-10-9 (E)-3-phenylpropenal 
• 4436-23-1 2-phenyloxetane 
• 108-94-1 cyclohexanone 
• 493-08-3 chromane 

Relevant academic research and scientific papers

Reductive lithiation of cyclic benzofused ethers: A source of oxygen-functionalised organolithium compounds

The reaction of 2,3-dihydrobenzofuran (1) with lithium and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB, 5%) in THF at 0°C for 1.5h, followed by addition of an electrophile [E+=H2O, tBuCHO, PhCH2CHO, Ph(CH2)2CHO, PhCHO, furfural, Me2CO, Et2CO, cyclopentanone, cyclohexanone, cyclooctanone, (-)-menthone] in THF at -78°C gives, after hydrolysis, compounds 3. Some diols 3 are easily transformed into 2-substituted chromans 6 under acidic reaction conditions. The reductive lithiation of chroman (7) at 20°C for 3h leads exclusively to the intermediate 8, which is formed through a dearylation process, and isomerises to the apparently more stable benzylic intermediate 9. The reaction of these intermediates with different electrophiles {E+=tBuCHO, PhCHO, furfural, Me2CO, [CH3(CH2)4]2CO, cyclopentanone, cyclohexanone, (-)-menthone, Ph2CO}, at -78°C in THF leads, after hydrolysis, to a mixture of regioisomers 10 and 11. The reaction of 2,3-benzofuran (12) with an excess of lithium and a catalytic amount of DTBB (5%) in THF at 0°C for 45min leads to dianionic intermediate 13 through a dealkylation process, which after hydrolysis gives 2-vinylphenol 14. In the case of 4H-chromene (15), reductive opening is performed at 20°C for 45min, a mixture of dearylation and dealkylation intermediates 16 and 17, respectively, is obtained (2:1 ratio) giving, after hydrolysis, 3-phenylpropanal (18) and 2-allylphenol (19).

γ-Lithioalkoxides via Reductive Lithiation of Oxetanes by Aromatic Radical Anions

Oxetanes are cleaved at 0 deg C in tetrahydrofuran by lithium 4,4'-di-tert-butylbiphenylide, giving lithium γ-lithioalkoxides which can provide 2-substituted tetrahydrofurans by trapping with aldehydes and ketones followed by acid cyclization of the resulting 1,4-diols; the cuprates of these dianions undergo conjugate addition and nucleophilic substitution reactions.