94098-84-7

Upstream product

• 764-13-6 2,5-Dimethyl-2,4-hexadiene 

Downstream Products

• 4723-10-8 racem. 2,5-dimethyl-hexa-1,5-diene-3,4-diol 
• 22520-37-2 dl-2,5-dimethylhexane-3,4-diol 
• 412346-29-3 (R)-1-((S)-3,3-Dimethyl-oxiranyl)-2-methyl-prop-2-en-1-ol 
• 114702-48-6 2-(3-Isopropenyl-oxiranyl)-propan-2-ol 

Relevant academic research and scientific papers

SENSITIZED PHOTO-OXYGENATION OF ACYCLIC CONJUGATED DIENES

Sensitized photo-oxygenation of a wide variety of acyclic 1,3-dienes was investigated.The 1,4-cycloaddition of singlet oxygen to acyclic conjugated dienes was closely related to the thermal Diels-Alder reaction in stereospecificity, and steric and electronic effects of substituents.Reactivity order of singlet oxygen toward conjugated dienes and isolated C-C double bonds was exhibited as follows: trisubstituted monoolefins > 2-substituted 1,3-dienes > disubstituted mono-olefins.

INTERACTIONS OF SINGLET OXYGEN WITH 2,5-DIMETHYL-2,4-HEXADIENE IN POLAR AND NON-POLAR SOLVENTS EVIDENCE FOR A VINYLOG ENE-REACTION

2,5-Dimethyl-2,4-hexadiene (1) was studied as a singlet oxygen acceptor in various solvents. 1 undergoes concomitantly the three well-known modes of singlet oxygen reactions: (1) the ene-reaction to give the allylic hydroperoxide 3, (2) the (4+2)-cycloaddition to give the endoperoxide 4, and (3) the (2+2)-cycloaddition to give the dioxetane 2.Beyond that (and in contrast to simple olefins), there are (4) "physical" quenching and (5) a "vinylog ene-reaction" to give the twofold-unsaturated hydroperoxide 5.The latter reaction represents a novel mode of singlet oxygen interaction with a substituted 1,3-diene. - Kinetic analysis shows that "physical" quenching, endoperoxide and vinylog ene-product formations proceed with solvent-independent rates; the rates of dioxetane and ene-product formations, however, are solvent-dependent. - A mechanism (Scheme 3) is proposed, according to which endoperoxide formation is due to a concerted singlet oxygen reaction with the s-cis-conformational isomer 1b; with the s-trans-isomer 1a, "physical" quenching and the vinylog ene-reaction proceed via a non-polar singlet diradical intermediate, whereas the ene-product formation occurs via a perepoxide-like transition state.In aprotic solvents, the dioxetane is mainly formed via a "tight-geometry intermediate", in methanolic solution via a solvent-stabilized zwitterion; the latter is also responsible for the formation of the methanol-addition product 6.