Aza-Diels-Alder reaction between N-aryl-1-oxo-1H-isoindolium ions and tert-enamides: Steric effects on reaction outcome.

The synthesis of 5-substituted 6,6a-dihydroisoindolo[2,1-a]quinolin-11(5H)-ones via [4 + 2] imino-Diels-Alder cyclization from N-aryl-3-hydroxyisoindolinones and N-vinyl lactams under Lewis acid-catalysed anhydrous conditions is reported. Reactions of N-(2-substituted-aryl)-3-hydroxyisoindolinones with N-vinylpyrrolidone under identical conditions resulted in the formation of 2-(2-substitued-aryl)-3-(2-(2-oxopyrrolidin-1-yl)vinyl)isoindolin-1-one analogues indicating steric hinderance as the cause of deviation. The probable mechanism of the reaction based on the results from X-ray crystallography and molecular modelling is discussed.

An efficient and expeditious synthesis of novel 2,2-dialkyl-2,3-dihydrobenzofurans from phenols and 2,2-dialkylacetaldehydes.

Reactions of 2,2-dialkylaldehydes with electronrich 2-naphthols and para-substituted phenols in presence of catalytic amount of p-TSA under closed vessel solvent-free microwave irradiation conditions resulted in formation of corresponding 2,2-dialkyl-1,2-dihydronaphtho[2,1-b]furans and 2,2-dialkyl-2,3-dihydrobenzofurans, respectively, in good to excellent yields. The effect of stoichiometry, temperature, and catalyst in reaction progress was systematically investigated. 14-Alkyl-14H-dibenzo[a, j]xanthenes was obtained as minor productswhen 2-naphthol and 6-bromo-2-naphthols were used as starting phenols. Simple phenols gave a lower yield of the 2,2-dialkyl-2,3-dihydrobenzofurans products than their electron-rich naphthalene counterparts. Also, xanthene-type products were not detected in case of simple phenols by GC­MS or column chromatography.

Camelia oil and soybean-camelia oil blend enhance antioxidant activity and cardiovascular protection in hamsters.

OBJECTIVES: The aim of this study was to examine the effects of several vegetable oils and blended oil composed of soybean and camellia oils on blood lipid reduction and antioxidative activity. METHODS: Forty male hamsters were fed an AIN-93 G diet for 1 wk, followed by dividing into five groups: control group-1 was fed a low-fat diet containing 5% oil for 6 wk, and the other four groups were fed high-fat diets with group-2 containing 14% palm oil, group-3 containing 14% camellia oil, group-4 containing 14% soybean oil, and group-5 containing 14% blended oil (8.4% soybean oil and 5.6% camellia oil) along with 0.2% cholesterol and 0.1% bile acid. RESULTS: High-fat diets raised serum triacylglycerol, total cholesterol, and aspartate aminotransferase in hamsters without affecting alanine aminotransferase. Compared with palm oil-containing diet, the other three high-fat diets reduced serum total cholesterol, low-density lipoprotein cholesterol, and the ratio of low-density lipoprotein to high-density lipoprotein cholesterol with an opposite trend for liver total cholesterol. However, compared with the control group, the serum high-density lipoprotein cholesterol level was raised for all four high-fat diets. The higher the degree of oil unsaturation, the higher the serum thiobarbituric acid reactive substances and the lower the liver triacylglycerol level and activities of fatty acid synthase, glucose 6-phosphate dehydrogenase, and malic enzymes. Both soybean and blended oils lowered the antioxidative activity of liver. CONCLUSION: Camellia and blended oils were more efficient than soybean oil in elevating serum high-density lipoprotein cholesterol and decreasing the ratio of low-density lipoprotein to high-density lipoprotein cholesterol in hamsters.