16737-07-8

Upstream product

• 77758-50-0 4-pentynyl-1-tosylate 
• 64701-59-3 Ethyl 1,2-dimethyl-2-hydroxycyclopentane-1-carboxylate 
• 5453-88-3 ethyl 1-methyl-2-oxocyclopentane-1-carboxylate 
• 64701-60-6 1,2-Dimethyl-cyclopenten-⁽²⁾-carbonsaeure-⁽¹⁾-aethylester 
• 93-55-0 1-phenyl-propan-1-one 
• 84884-01-5 1,2-dimethylcyclopent-2-ene carboxylic acid 
• 591-51-5 phenyllithium 

Relevant academic research and scientific papers

α-Carbonyl Cations in Sulfoxide-Driven Oxidative Cyclizations

The selective, metal-free generation of α-carbonyl cations from simple internal alkynes was accomplished by the addition of a sulfoxide to a densely substituted vinyl cation. The high reactivity of the α-carbonyl cations was found to efficiently induce hydrogen and even carbon shift reactions with unusual selecivities. Complex compounds with highly congested tertiary and all-carbon-substituted quartenary carbon centers can thus be accessed in a single step from simple precursors. Mechanistic analysis strongly supports the intermediacy of the title compounds and provides a simple predictive scheme for the migratory aptitude of different substituents.

174. Photochemical α-Cleavage of β, γ-Unsaturated Aryl Ketones: Competition between Recombination/Disproportionation and Dissociation in Geminate Singlet and Triplet Radical Pairs

The photolysis of (R)-(+)-phenyl and (R)-(+)-p-anisyl 1, 2, 3-trimethylcyclopent2-enyl ketone (1, 2) and the corresponding rac-1- and 3-desmethyl analogs (3, 4) led to isomerization due to formal 1,3 aroyl migration and to formation of aryl aldehydes (7, 8), dienes (9, 10) and dimers (5, 6) of the cyclopentenyl radical. Evidence obtained from a chiroptical and mass spectrometric analysis of a crossing experiment and from photolytic CIDNP measurements including the use of CCl4 as a free radical scavenger, supports the conclusion (1) : that the ketones undergo photochemical α-cleavage predominantly in the triplet state ; (2) : that recombination and disproportionation reactions within the geminate singlet and triplet aroyl/allyl radical pairs (11) compete with the dissociation into free radicals (12) ; (3) : that ketone isomerization by paths not involving polarizable radical intermediates is unimportant ; (4) : that no triplet oxa-di-π-methane type rearrangement products are formed.