Chiral Synthesis of the Intermediate of (-)-Gibberellin A_(12)

(-)-Dimethyl(1R,4aS),4a-dimethyl-6-nitro-1,2, 3,4, 4a-pentahydrofluorene-1, 9 -dicarboxylate (1) was synthesized from (R)-(+)-2 -methyl- 2 -(2 -nitrovinyl)-δ-valerolactone(2),which constitutes a formal total Synthesis of (-)-gibberellin A_(12).

The Synthesis of New Sulfur-containing Chiral Macrocyclic Ligands

Five new chiral sulfur-containing macrocyclic ligands which can be used in chiral recognition to guests have been synthesized and characterized

SYNTHESIS OF DIAZA CROWN ETHER CHIRAL LIQUID CRYSTAL

A chiral liquid crystal crown ether containing diaza-18-crown-6 was synthesized with the help of CPK atomic model and in the meantime a nonchiral liquid crystal crown ether of alike structure was also synthesized for comparison, indicating that only the former was asymmetric. The present work represents the first attempt of the investigation in chiral liquid crystal crown ether, thus providing basis for further research into problems as such.

SYNTHESIS OF CHIRAL MIXED-LICAND COMPLEXES AND THEIR USE IN ASYMMETRIC SYNTHESIS OF CHRYSANTHEMIC ACID

Several chiral mixed-ligand complexes have been synthesized and their efficiency as catalysts for the asymmetric synthesis of chrysanthemic acid tested.

Catalytic Asymmetric Diastereodivergent Synthesis of 2-Alkenylindoles Bearing both Axial and Central Chirality

The catalytic asymmetric diastereodivergent synthesis of axially chiral 2-alkenylindoles was established via chiral phosphoric acid-catalyzed addition reactions of C3-unsubstituted 2-alkenylindoles with o-hydroxybenzyl alcohols under different reaction conditions.Using this strategy,two series of 2-alkenylindoles bearing both axial and central chirality were synthesized in a diastereodivergent fashion with moderate to high yields and good stereoselectivities(up to 99%yield,95:5 er,>95:5 dr).Moreover,theoretical calculations were performed on the key transition states leading to different stereoisomers,which provided an in-depth understanding of the origin of the observed stereoselectivity and diastereodivergence of the products under different reaction conditions.More importantly,these 2-alkenylindoles were utilized in asymmetric catalysis as chiral organocatalysts and in medicinal chemistry for evaluation of their cytotoxicity,which demonstrated their potential applications.This study has not only established the catalytic atroposelective synthesis of axially chiral 2-alkenylindoles,but also provided an efficient strategy for catalytic asymmetric diastereodivergent construction of indole-based scaffolds bearing both axial and central chirality.

Synthesis of a-carbethoxy substituted chiral alkyl nitronic esters

Of organic compounds,nitronic esters are a group of unusual compounds.Accordingto their chemical formula（R1R2C=NO2R3）,they might be formally obtained fromcondensation of aci-nitro compounds（intronic acids）and alcohols with an equivalentamount of water eliminated.In fact,neither could nitronic esters be produced by thismethod,nor could they be hydrolyzed into nitronic acids and alcohols.Since they