59121-52-7

Upstream product

• 7519-74-6 (+/-)-thiocampher 
• 53402-10-1 thiocamphor 
• 52078-93-0 (1R)-(-)-thiocamphor 

Downstream Products

• 53402-10-1 thiocamphor 
• 464-49-3 (1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one 

Relevant academic research and scientific papers

Photochemical Oxidation of Thioketones by Singlet Molecular Oxygen Revisited: Insights into Photoproducts, Kinetics, and Reaction Mechanism

Photosensitized oxidation of trimethyl[2.2.1]bicycloheptane thioketones by 1O2 can yield more photoproducts than exclusively ketones and sulfines. Moreover, the ketone/sulfine ratio can be reversed when protic conditions and high thioketone concentrations are used, conversely to earlier results reporting ketones as the main photoproducts. A new mechanistic proposal for sulfine formation is suggested following intermolecular oxygen transfer from a peroxythiocarbonyl intermediate to a second thioketone molecule. Reaction quantum yields (10-5-10-2) depend on the reaction conditions and time. Sulfine production reaches a maximum at short irradiation times, whereas decomposition to the corresponding ketone is observed at long reaction times. When the thioketone substrate has a hydrogen atom at the α position a peroxyvinylsulfenic acid intermediate can be formed by proton transfer. Reaction of this intermediate with another thioketone molecule can yield more sulfine and its tautomeric vinylsulfenic acid, which dimerizes in situ to the thiosulfinate. The hydroperoxyl group of the peroxyvinylsulfenic acid can also rearrange to the α position, and by reaction with the starting thioketone, α-hydroxy thioketone and additional sulfine can be formed, while dehydration yields the α-oxo thioketone. In situ [2 + 2] and [4 + 2] self-cycloaddition of the α-oxo thioketone yields significant amounts of the corresponding adducts at prolonged irradiation times.

Reaction of Thioketones with Carbonyl Oxides and 3,3-Dimethyl-1,2-dioxirane. Cycloaddition vs. Oxygen Atom Transfer

The ozonolysis of vinyl ethers 1a, b in the presence of adamantane-2-thione 4a and bicyclononan-9-thione 4b gave in each case the corresponding thioozonides 5a-c in moderate yields, whilst ozonolysis of a mixture of vinyl ethers 1a-d and thiobenzophenone derivatives 4f-h gave the corresponding thione S-oxides 8f-h in isolated yields of 10-40percent, together with the benzophenones 7f-h. 3,3-Dimethyl-1,2-dioxirane, generated in situ from the reaction of acetone and 'oxone' (2KHSO5-KHSO4-K2SO4), transferred an oxygen atom to compounds 4a, f, g, i providing the thione S-oxides 8a, f, g, i in 29-97 percent yield.

STERIC ASPECTS OF THE OXIDATION OF THIOKETONES BY SINGLET OXYGEN

Singlet oxygen oxidation of dialkyl thioketones yields the corresponding ketones and in some cases sulfoxides in varying amounts.Steric considerations on the reactive zwitterionic/diradical intermediates have been invoked to rationalise the product distribution.