Studies On Synthesis Of Tetraasterane By [2+2] Photoreaction

In the dissertation, we summarized the developement of [2+2] photo-cycloaddition in the synthesis of cyclobutane and cages on the base of the importance in the synthesis of cage compounds. The studies on the synthesis of tetraasterane using [2+2] photo-cycloaddition have been determined as our purposes. All the results should be guide to the synthesis of diazatetraasterane, tetraazatetraasterane and dioxatetraasterane. The synthesis of 3,9-diazatetraasterane using [2+2] photo-cycloaddition. was studied in detail. In order to decrease the affection of groups, diethyl 1,4-dihydropyridine-3,5-dicarbonate(59) was chosen as the starting material, and the factors were investigated, such as the source of ultralight, the concentration of solution, the period of reaction, the type of solvent and so on. Three different photodimers have been achieved, one is cage dimmer—3,9-diazatetraasterane, and the others are syn-and trans-dimmers, the configurations were confirmed by the data X-ray diffraction of their single crystals. They are tetraethyl 3,9-diazahexacyclo [6.4.0.02.7.04.11.05.10]-dodecane-1,5,7,11-tetracarboxylate(54),tetraethyl syn-1,5,8,8bβ-tetrahydrocyclobuta[1,2-b:3,4-b']dipyridine-3,4aβ,7,8aβ(4H,4bβH)-tetracarboxylate(63a) , tetraethyl anti-syn-1,5,8,8bβ-tetrahydrocyclobuta [1,2-b:3,4-b']dipyridine-3, 4aβ,7,8aβ(4H,4bβH)-tetracarboxylate(63b). The synthesis of 59 by the microwave-assisted was also studied, the results show that 59 was obtained in about 50% yield with the simple reactants such as (HCHO)n, HCHO/H2O, (CH2)6N4, NH4OAc, NH3/H2O, NH4HCO3 and (NH4)2CO3. The synthesis of tetraasterane(all carbon) and 3,6,9,12-tetraazatetraasterane using [2+2] photo-cycloaddition was studied. Using ethyl bicycle [2.2.1]heptadiene -2-carbonate, intramolecular cycloaddition product but not dimer has been achieved on irradiation; using 4-methyl-1,4-cyclohexadiene-1-carbonate, it has been showed to undergo isomerization easily, but not undergo [2+2] photo-cycloaddition. 1,4-dihydropyrazine(70) was undergoing the [2+2] photo-chemical reaction, the product was obtained which is tetraethyl 3,6,9,12-diazahexacyclo [6.4.0.02.7.04.11.05.10]...