60604-24-2

Upstream product

• 3561-67-9 bis(phenylthio)methane 
• 108-94-1 cyclohexanone 
• 1033082-97-1 C₁₃H₂₀ 
• 1033082-89-1 13,13-dibromodispiro[5.0.5.1]tridecane 
• 253797-54-5 1-[(1-hydroxycyclohexylphenylsulfanyl)methyl]cyclohexanol 
• 253797-62-5 1-(cyclohexylenemethyl)cyclohexanol 
• 56547-92-3 exifone 

Relevant academic research and scientific papers

Reactivity of 13,13-dibromo-2,4,9,11-tetraoxadispiro[5.0.5.1]tridecane toward organolithiums: Remarkable resistance to the DMS rearrangement

(Chemical Equation Presented) Reactions of dibromocyclopropane 2a, containing two spiro-fused 1,3-dioxane rings, with MeLi gave only the methylation products 8 and 9 even at elevated temperatures. In contrast, the cyclohexane analogue 2b treated with MeLi underwent a smooth rearrangement to bicyclo[1.1.0]butane 11b at -78, -10, or +35 °C. Treatment of 2a with PhLi gave the α-Ph anion 13 as the only product, which underwent smooth methylation with MeI to give 14. Under the same conditions, 2b with PhLi gave bicyclo[1.1.0]butane 11b accompanied by bromophenyl derivative 8b. Treatment of either dibromide with f-BuLi gave a mixture of products including debrominated cyclopropanes 12. Experimental results were augmented with DFT calculations for salts 23 and MP2//DFT-level calculations for carbenes 22. They demonstrated a higher stability of the dioxane α-bromo anion with respect to α-elimination by 4.8 kcal/mol and also a lower tendency of the carbene 22a to undergo rearrangement by 4.0 kcal/mol than the cyclohexane analogues. These differences have been attributed to the inductive effect of the four oxygen atoms, which results in lower LUMO energy, the higher positive charge at the carbenic center, and the overall more electrophilic character of carbene 22a as compared to the cyclohexane derivative 22b. The rearrangement of carbenes 22 to the corresponding allenes 1, the thermodynamic products, requires a higher activation energy ΔG?298 by 4.2 kcal/mol for dioxane and 6.4 kcal/mol for cyclohexane derivatives than for the formation of the bicyclo[1.1.0]butanes 11. The ΔG?;298 for intramolecular insertions to the C-H bond is low and calculated as 6.0 kcal/mol for dioxane 22a and 2.0 kcal/mol for the formation of cyclohexane 22b.

Polylithiation of thioethers: A versatile route for polyanionic synthons

The successive reaction of phenyl vinyl thioether (1) with n-butyllithium and an electophile [E1=PhCHO, (CH2)4CO, (CH2)5CO] in THF at - 78°C gives, after hydrolysis, the expected methylenic hydroxy thioethers (2). Deprotonation of 2 with n-butyllithium followed by a DTBB-catalysed lithiation and reaction with a second electrophile [E2=tBuCHO, PhCHO, Me2CO, (CH2)5CO], at - 78°C, gives after hydrolysis the corresponding methylenic diols 3. The same diols can be prepared starting from 1 in a one-pot process without isolation of the hydroxy thioether 2. The same methodology was applied to the cyclopropyl phenyl thioether (4), cyclopropyl 1,3-diols 5 {E1=tBuCHO, PhCHO, [Me(CH2)4]2CO, (CH2)5CO, (CH2)7CO; E2=tBuCHO, Me2CO, (CH2)5CO} being isolated in moderate yields. The successive treatment of bis(phenylthio)methane (7) with: (a) n-butyllithium at 0°C, (b) a carbonyl compound [E1=tBuCHO, Me2CO, Et2CO, (CH2)5CO] at - 40°C, (c) lithium and catalytic amount of DTBB (5%) and (d) a second carbonyl compound [E2=iPrCHO, tBuCHO, Me2CO, Et2CO, (CH2)5CO] both at - 78°C leads, after hydrolysis, to the expected dihydroxy thioethers 8. When after step (d), a second DTBB-catalysed lithiation is performed at temperatures ranging between - 78 and 20°C, the corresponding allylic alcohols 9 were isolated. Finally, treatment of alcohols 9 with a few drops of 6 M hydrochloric acid gives dienes 10 in almost quantitative yields.

Methane-derived polyanionic synthons from bis(phenylthio)methane

Successive treatment of bis(phenylthio)methane (1) with (a) n-butyllithium at 0°C, (b) a carbonyl compound [(t)BuCHO, Me2CO, Et2CO, (CH2)5CO] at -40°C, (c) lithium and a catalytic amount of DTBB (5%) and (d) a s