Synthetic Studies Of 4-Keto-Clonostachydiol And Guanidine-Catalyzed Reactions

The thesis aims at the studies on synthesis of 4-Keto-Clonostachydiol andGuanidine-Catalyzed Reactions. It consists of the following three parts:Part 1:Catalytic, enantioselective allylation reaction and its applications in synthesis (review)The categories, mechanism of allylation, especially the catalytic enantioselectiveallylation in the past 10 years and the applications in total synthesis were intruduced.Part 2: Asymmetric Total Synthesis of 4-keto-clonostachydiolThe first total synthesis of the 14-membered natural macrocyclic bislactone4-keto-clonostachydiol, along with its enantiomer, has been accomplished in 13 stepswith overall yields of 8.4% and 8.0%, respectively, from commercially available(S)-propyleneoxide. The synthesis was the use of reactions such as the Sharplessasymmetric dihydroxylation, Wadsworth-Horner-Emmons Olefination, Mitsunobureaction, ring-closing metathesis (RCM), Keck esterification, Yamaguchi Conditon.The absolute configuration of 4-keto-clonostachydiol 1 has been revised as (5S, 10S,13S)and further confirmed by Mosher's method.Part 3:Guanidine-catalyzed Henry reaction and Knoevenagel condensationA series of guanidine catalysts have been designed and synthesized. The catalystis easily accessible and shown to be highly efficient for Henry reaction andKnoevenagel condensation. Especially in terms of milder reaction conditions (at roomtemperature) and that anhydrous solvents or reagents and inert atmosphere conditionsare not required.