In the first two parts of this thesis mainly focused on carbon radical reaction promoted by Manganses(Ⅲ):(1) Mn(acac)3 reacted with nitroalkenes underwent ligand-transferring process to synthesize dihydronfuran derivatives, which were further deoxidized of the nitro-group to obtain varies of pyrrole derivatives.

The reaction mechanism for synthesis of 2,5-dihydrofuran by the ring closing reaction of 2-butene-1,4-diol using acidic resin as catalyst was studied.

The Circular Dichroism of Some β-Dihydroagarofuran Polyesters;

In order to find new active compounds,the structure of 1β,2β,4α,6α,8β,9α,13-hepthydroxy-β-dihydroagarofuran was simplified to be 1β,4α,6α,9α-tetrahydroxy-2β,12-ether-β-dihydroagarofuran,and seven new dihydroagarofuran ether analogues were synthesized using 1β,4α,6α,9α-tetrahydroxy-2β,12-ether-β-dihydroagarofuran as staring materials.

Based on the data in literatures and our research results in recent years, the paper dis cussed the α,β,γeffects on the 13C NMR and stereochemisry of β-dihydroagarofuran when the parent skeleton was substituted by acyloxy or hydroxy groups at the pdgitions C2,C4,C6,C8 and C13 which would be very useful for the research on the new chemical structures of this kind of compounds.

Arsonium bromides 1 reacted with electron-deficient olefins containing one p-trifluoromethyl-phenyl and two other electron withdrawing groups 2 or 3 in the presence of K2CO3 to form cis-1,2-cyclo-propane or cis-2,3-dihydrofuran derivatives containing the p-trifluoromethylphenyl group 4 or 5 in high yields with high stereoselectivity.