Stereospecific synthesis of (R)- and (S)-S-adenosyl-1,8-diamino-3-thiooctane, a potent inhibitor of polyamine biosynthesis. Comparison of asymmetric induction vs enantiomeric synthesis
作者:Chin Liu、James K. Coward
DOI:10.1021/jm00111a026
日期:1991.7
induction and the other involving an enantiomeric synthesis. The latter route gave the desired products in greater than 96% de, whereas the synthesis based on asymmetric induction resulted in only 80% de in the final product. Evaluation of the two diastereomers as inhibitors of spermidine synthase showed that the R diastereomer is a more potent inhibitor than the S diastereomer.
Synthetic study of spiroiridal triterpenoids: construction of functionalized spiro[4.5]decane skeleton using Claisen rearrangement of 2-(alkenyl)dihydropyran
The spiroiridal triterpenoids show interesting biological activities, such as a piscicidal activity, PKC activation, and molluscicidal activity. Herein, the first synthesis of the functionalized spiro[4.5]decane skeleton of spiroiridal triterpenoids was accomplished. The characteristic features of the present synthesis are the Claisen rearrangement of 2-(alkenyl)dihydropyran developed by our group and the efficient transformation into the key intermediate (+)-6. (C) 2014 Elsevier Ltd. All rights reserved.
LIU, CHIN;COWARD, JAMES K., J. MED. CHEM., 34,(1991) N, C. 2094-2101
作者:LIU, CHIN、COWARD, JAMES K.
DOI:——
日期:——
A Short and Productive Synthesis of (R)-α-Lipoic Acid
(R )-α-Lipoicacid is synthesized in seven steps from the base chemicals methyl acetoacetate or Meldrum’s acid and monomethyl adipate. The key steps are the introduction of the stereogenic center by fermentative or homogeneously catalyzed hydrogenation of 3-oxooctanedioic acid diester to (3S)-3-hydroxyoctanedioic acid diester and its regioselective reduction to (6S)-6 ,8-dihydroxyoctanoic acid ester
The synthesis of methyl (S)-(-)-6,8-dihydroxyoctanoate as a precursor of (R)-(+)-α-lipoic acid was accomplished by using methyl (S)-(-)-(2-oxocyclohexyl)acetate, which had been obtained from baker’s yeast reduction, as a chiral starting material.