51566-98-4

Upstream product

• 36284-91-0 N-(1-norbornyl)-N',N'-dimethyl-N-nitrosourea 
• 110-82-7 cyclohexane 
• 41798-00-9 acide bicyclo<2.2.1>heptane peroxycarboxylique-1 
• 89849-39-8 Di(1-adamantyl)(1-norbornyl)methanol 
• 86458-82-4 adamant-1-ylbicyclo<2.2.2>oct-1-ylnorborn-1-ylcarbinol 
• 33175-47-2 Norborneol-⁽¹⁾-p-toluolsulfonsaeureester 
• 249904-46-9 1-Nitrooxy-bicyclo[2.2.1]heptane 
• 67-56-1 methanol 
• 433713-11-2 3-(bicyclo[2.2.1]hept-1-yloxy)-3-chloro-3H-diazirine 

Downstream Products

• 98963-67-8 Diphenyl-1-norbornyl-phosphat 
• 92787-87-6 1-norbornyl benzoate 
• 249904-42-5 methanesulfonic acid bicyclo[2.2.1]hept-1-yl ester 
• 33175-47-2 Norborneol-⁽¹⁾-p-toluolsulfonsaeureester 
• 86505-42-2 3-ethylcyclopentanone 
• 589-92-4 1-methylcyclohexan-4-one 
• 497-38-1 Norbornan-2-on 
• 141270-02-2 3-[exobicyclo(2.2.1)hept-5-en-2-yloxy]-4-methoxybenzaldehyde 

Relevant academic research and scientific papers

Bridgehead carbocations via carbene fragmentation: Erasing a 1010 kinetic preference

1-Norbornyloxychlorocarbene (1-NorOCCl), 1-bicyclo[2.2.2]octyloxychlorocarbene (1-BcoOCCl), and 1-adamantyloxychlorocarbene (1-AdOCCl) were generated in dichloroethane (DCE) by photolysis of the appropriate diazirines. The exclusive product in each case was the bridgehead alkyl chloride formed by fragmentation of the carbene to [R+ OC Cl-] ion pairs, loss of CO, and cation-anion collapse. In mixtures of methanol and DCE, each carbene gave three products: RCl, ROH, and ROMe. RCl and ROMe resulted from competition between ion pair collapse and methanol capture of the cation. ROH resulted from methanol capture of the carbene (before fragmentation), followed by eventual methanolysis and hydrolysis of ROCH(Cl)OMe. The ratios of carbene capture to carbene fragmentation fell in the order 1-NorOCCl > BcoOCCl > 1-AdOCCl; 1-Nor+ was the least stable cation and the slowest to form by fragmentation, so that this carbene was the most readily captured. This trend was accentuated in methanol-pentane mixtures, where ionic fragmentation was further slowed in the less polar solvent. Laser flash photolysis with either UV or time-resolved infrared (TRIR) monitoring permitted the determination of the absolute rate constants for fragmentations of the carbenes in DCE at 25 °C. The rate constants (s-1) were: 1-NorOCCl (3.3 × 104), 1-BcoOCCl (1.5 × 105), and 1-AdOCCl (5.9 × 105). The rate constants decreased in the order of increasing strain in the resulting bridgehead carbocation, but the range of rate constants was compressed to a factor of only ～18. This constrasts with the factor of 1010 by which the acetolysis of 1-AdOTs at 70 °C exceeded that of 1-NorOTs. The fragmentation of 1-NorOCCl to the ion pair was 3 × 1015 times faster than the acetolysis of 1-NorOTs. The activation energies were measured as 9.0 kcal/mol (log A = 11.2 s-1) for the fragmentation of 1-NorOCCl and 4.4 kcal/mol (log A = 8.44 s-1) for that of 1-BcoOCCl both in DCE. B3LYP/6-31G* computed activation energies in simulated DCE were 14.6 and 2.7 kcal/mol, respectively. Copyright

Competing radical- and anion-mediated pathways in the reduction of bridgehead tosylates with lithium aluminium hydride

Reaction of norborn-1-yl tosylate with lithium aluminium hydride in boiling tetrahydrofuran affords a mixture of norbornan-1-ol accompanied by the ring-opened products 4-methylcyclohexanol and 3-ethylcyclopentanol as their cis/trans isomers, as well as p-thiocresol and p-tolyl disulfide. Evidence strongly suggests that the reaction is mediated by the norborn-1-yloxy radical rather than the norborn-1-yloxy anion. The process is initiated by very slow acyl oxygen fission of the norbornyl tosylate, followed by reduction of the derived p-toluenesulfinate ion to give the p-thiocresoxide anion. Transfer of an electron from the latter to the substrate and decomposition of the derived norborn-1-yl tosylate radical anion leads to the norborn-1-yloxy radical which, upon ring opening, generates the monocyclic alcohols via the corresponding ketones. It is noteworthy that, when norborn-1-yl mesylate is exposed to lithium aluminium hydride, it yields norbornan-1-ol exclusively. In the absence of an efficient electron-transfer agent, the mechanism of reaction of norborn-1-yl mesylate is suggested to involve acyl oxygen fission only.

Interpretation of the Reactivity of Benzyl Free Radical towards Peroxyacids in Terms of Orbital Interactions. Competition between Energy Gap Control and Overlap Control

The factors which control the reactivity of alkyl free radicals R. in reaction (i) are studied.The reactivity of R. in (i) depends on the key orbital interaction between the SOMO of the radical and the LUMO of the peroxyacid.This interaction involves two contributions: (i) the energy gap SOMO-LUMO and (ii) the overlap SOMO-LUMO.In reaction (i) the main factor is overlap control which depends on spin delocalisation in the radical R..This proves that reaction (i) does not involve electron transfer.The energy gap control, which depends on the nucleophilic character of R., is only observed when the first factor is constant along a series of R..

N-Nitroso- and N-Nitrotrialkylureas and Their Decomposition

The synthesis and decomposition of N-(n-butyl)-N',N'-dimethyl-N-nitrosourea (2a), N-(n-butyl)-N',N'-dimethyl-N-nitrourea (3a), N',N'-dimethyl N-(1-norbornyl)-N-nitrosourea (2b), N',N'-dimethyl-N-(1-norbornyl)-N-nitrourea (3b) are described.Several of the compounds show complex NMR spectra ascribable to rotational isomerism.Decomposition of 2a and 3a gave n-butyl N,N-dimethylcarbamate and tetramethylurea, while decompostion of 2b and 3b in methylene chloride gave 1-norbornyl N,N-dimethylcarbamate and 1-norbornyl chloride.These products are formed via diazotic acid derivatives and carbonium ion pairs; the reaction mechanism is essentially the same as that established for the closely related N-nitrosoamides.In concentrated solutions, nitrosourea 2a yielded a new product, amino acid 20.

MIGRATION APTITUDES OF CYCLIC AND POLYCYCLIC BRIDGEHEAD GROUPS IN THE CRIEGEE REARRANGEMENT

The migration aptitudes of cyclic and polycyclic bridgehead groups in the Criegee Rearrangement support ?-neighbouring group participation by pentacoordinated bonding and vertical charge stabilisation in the migrating group and therefore favour transition state 2b and not 2a.

ETUDE DU CARACTERE NUCLEOPHILE DES RADICAUX LORS DE LA REACTION DE TRANSFERT SUR LA LIAISON O-O DES PERACIDES

Peracids RCO3H yield free radicals R. which react either with the peracid or with solvent giving the alcohol ROH and the hydrocarbon RH.The nucleophilic character of the free radicals was modified either by substitution of the carbon bearing the odd electron by inductive groups or by changing the free radical hybridation by the means of blocked structures such as cyclic or bicyclic free radicals.For each R., the measurement of the ratio ROH/RH establishes a reactivity scale for R. with the peracid O-O bond.This reactivity does not depend on free radical stability but depends strongly on nucleophilic character.A primary free radical is less reactive than a secondary one, and is much less reactive than a tertiary one.A bridgehead free radical as the bicycloheptyle-1 does not react with the peracid.These results are interpreted to indicate a transition state with charge transfer (polar effect), the peracid being electrophilic and the free radical nucleophilic; PMO theory is discussed.