Intramolecular Heteroatom and Styryl Diels-Alder Reactions, Asymmetric Cycloadditions of Chiral 3-Phenylallyl Maleic Esters.

Polycyclic aryl naphthalene and tetralin dihydro arylnaphthalene lactone lignans possess anticancer and antibiotic activity. Related furo[3,4-c]pyranones, typified by the sequester-terpenoid isobolivianine, show similar antiproliferative bioactivity. Efficient syntheses of compounds featuring these polycyclic cores have proven challenging due to low yields and poor stereoselectivity. We report the synthesis of chiral cinnamyl but-2-enanoates and 3,3-diphenylallyl-but-2-enoates 1 as new Diels-Alder substrates. These compounds undergo [4 + 2]-cycloadditions to give furo[3,4-c]pyranones 2 in good yield (70%) and diastereoselectivity (7:1), together with naphthyl 3 and dihydronaphthyl tetralins 4 as minor products. Molecular structures and stereochemistries of the major products were verified using X-ray diffraction. Density functional theory calculations revealed that the cycloaddition process involves a bispericyclic/ambimodal process where there is a single transition state that leads to both intramolecular styryl Diels-Alder (ISDA) 3, 4 and intramolecular hetero Diels-Alder (IHDA) cycloadducts 2. With the elevated temperature conditions after cycloaddition, the resulting ISDA cycloadduct either undergoes [3,3]-sigmatropic rearrangement to the more stable major IHDA product or aromatization leading to the phenyltetralin.

Using infographics in disseminating healthy lifestyle information on social media is likely to increase uptake and sharing.

BACKGROUND: Infographics facilitate rapid information dissemination with enriched eye-catching content on social media, but it is unclear what factors affect the adoption of information presented in this way. OBJECTIVES: We tested whether the Information Acceptance Model applies to infographics on healthy lifestyle and fitness topics. METHODS: Two hundred and four university students were invited to participate in an online survey on their acceptance after reading some healthy lifestyle and fitness topics infographics shared on social media. The data collected were analysed using Partial Least Square path modelling. RESULTS: The results confirmed information usefulness as a predictor of information adoption; attitude towards information and information adoption were the predictors of behavioural intention. Information credibility and attitude towards information, but not information quality and needs, were significantly related to information usefulness. Social media usage and education level were factors affecting infographics impressions. DISCUSSION: Results support most hypotheses. It confirms information usefulness as a predictor of infographics adoption. Attitudes towards information and information adoption are predictors of behavioural intentions of following healthy lifestyle and fitness suggestions through social media infographics. CONCLUSION: Social media facilitates interpersonal communication, information exchange and knowledge sharing, and infographics may draw people into healthy lifestyle and fitness information items relevant to them.