0000000000240284
AUTHOR
C. L. Garcia
ChemInform Abstract: A Non-Catalyzed Ring-Opening Aminolysis Reaction of Sesquiterpene Lactones.
Abstract Santonin (1) and other sesquiterpene lactones (6–10) react cleanly with pyrrolidine at room temperature to afford γ-hydroxyalkylamides, which by elimination with mesyl chloride in pyridine-benzene at 80°C give unsaturated alkylamides.
ChemInform Abstract: Ring-Opening Aminolysis of Sesquiterpene Lactones: An Easy Entry to Bioactive Sesquiterpene Derivatives. Synthesis of (+)-β-Cyperone and (-)-Eudesma-3,5-diene from Santonin.
Abstract Santonin ( 1 ) and other sesquiterpene lactones ( 2–3 ) react with pyrrolidine and other cyclic secondary amines to afford γ-hydroxyamides, which by elimination with mesyl chloride in pyridine-benzene at 80°C give unsaturated amides 4a-4c, 5a-5c and 6 . Starting from amides 5a-5c a series of bioactive compounds against Locusta migratoria have been prepared, differing in the oxidation states of the C-3 and C-12 carbon atoms. Starting from amides 5a and 6 two conjugated diene eudesmanes (+)-β-cyperone ( 15 ) and (−)eudesma-3,5-diene ( 19 ) have been prepared involving an elaboration of the amide group of the side chain of the eudesmane skeleton.
Synthesis of two natural 8-oxo-β-cyperone derivatives from (−)-santonin.
Abstract This paper reports on the chemical transformations of (−)-santonin into (+)-8-oxo-β-cyperone and (+)-12-hydroxy-8-oxo-β-cyperone involving 8-oxo group introduction and elaboration of the side chain.
ChemInform Abstract: Synthesis of Two Natural 8-Oxo-β-cyperone Derivatives from (-)- Santonin.
Abstract This paper reports on the chemical transformations of (−)-santonin into (+)-8-oxo-β-cyperone and (+)-12-hydroxy-8-oxo-β-cyperone involving 8-oxo group introduction and elaboration of the side chain.
Reductive cleavage of 2,2,2-trichloroethyl esters with sodium telluride
Abstract Carboxylic acids are regenerated from their 2,2,2-trichloroethyl esters by treatment with sodium telluride in dimethylformamide in smooth conditions and with good yields. The reaction conditions are compatible with other functional and protective groups such as methyl ester, acetate or tert-butyldimethylsilyl ethers.
Oxidation of N-Acyl-pyrrolidones to Imides with CrO3·3,5-dimethylpyrazole
Abstract N -Acyl-pyrrolidones are easily obtained by treatment of N -acyl-pyrrolidines with CrO 3 ·3,5-dimethylpyrazole complex (CrO 3 ·3,5-DMP) at room temperature.
ChemInform Abstract: Reductive Cleavage of 2,2,2-Trichloroethyl Esters with Sodium Telluride.
Abstract Carboxylic acids are regenerated from their 2,2,2-trichloroethyl esters by treatment with sodium telluride in dimethylformamide in smooth conditions and with good yields. The reaction conditions are compatible with other functional and protective groups such as methyl ester, acetate or tert-butyldimethylsilyl ethers.
A non-catalyzed ring-opening aminolysis reaction of sesquiterpene lactones
Abstract Santonin (1) and other sesquiterpene lactones (6–10) react cleanly with pyrrolidine at room temperature to afford γ-hydroxyalkylamides, which by elimination with mesyl chloride in pyridine-benzene at 80°C give unsaturated alkylamides.
Synthesis of 9-oxyfunctionalized eudesmanes from artemisin
Abstract Artemisin ( 1 ) was transformed into two natural sesquiterpenoids 2 and 3 in a sequence which involves functionality transfer from C 8 to C 9 and further elaboration of the A ring and the lactone moiety.