185140-33-4

Upstream product

• 994-30-9 triethylsilyl chloride 
• 38818-54-1 (1Z)-3-methyl-1-(2',2',6'-trimethylcyclohex-1'-enyl)-1-buten-3-ol 
• 35031-06-2 (Z)-β-ionone 

Relevant academic research and scientific papers

Abnormally high reactivity of the vinyl hydrogen toward singlet oxygen in a twisted 1,3-diene

In a significantly twisted 1,3-diene, a regio-selective ene-reaction of the vinyl hydrogen rather than the allyl hydrogen with singlet oxygen was observed, and this phenomena is rationalized by considering largo σ*-π orbital interactions between the vinyl

Photosensitized oxygenation of twisted 1,3-dienes: Abnormally higher reactivity of vinyl hydrogen rather than allyl hydrogen toward singlet oxygen

As one of the novel examples to investigate the characteristic reactivity of significantly twisted 1,3-dienes, the photosensitized oxygenation of two types of significantly twisted 1,3-dienes, cis-βionol derivative 2 and acyclic derivative 11, is investigated. Photosensitized oxygenation of 2a-f and 11a-e revealed that the vinyl hydrogen Ha was more reactive than the allyl hydrogen Hb. Thus, phenyl derivative 2e and tert- butyl-substituted compound 11d selectively produced allenes 3e and 13d in 67% and 75% yield resulting from the ene reaction of the vinyl hydrogen Ha rather than allyl alcohols 4e and 14d resulting from the allyl hydrogen abstraction in 24% and 8% yield, respectively. Furthermore, in the case of methyl- substituted compound 11b, the extent of the inherent reactivity of the vinyl hydrogen Ha was similar to that of the allyl hydrogen Hc. On the basis of X- ray analysis and MM and MO calculations, the discovered abnormally higher reactivity of the vinyl hydrogen would be rationalized by considering mainly the large σ*-π orbital interaction between the vinyl C-H bond and another double bond in significantly twisted 1,3-dienes resulting from calculations of HOMO electron densities.