An efficient Amano PS-catalyzed chemo-, regio- and enantioselective hydrolysis of (±)-2,3-di-O-acetyl-2-C-methyl-d-erythrono-1,4-lactone: a facile preparation of bioactive natural products (−)-saccharinic acid lactone and potassium (2R,3R)-2,3,4-trihydroxy-2-methylbutanoate
摘要:
Saccharinic acid lactone (-)-1a is a suitable building block for the synthesis of many bioactive natural products. Amano PS-induced chemo-, regio- and enantioselective hydrolysis of diacetyl lactone (+/-)-3 has been carried out to obtain (-)-1a in 46% yield with 99% ee and diacetyl lactone (+)-3 in 49% yield with 99% ee. The Amano PS-catalyzed enantioselective acylation of (+/-)-1a with vinyl acetate as an acyl donor was relatively less efficient and furnished (-)-7 in 31% yield with 99% ee and (+)-1a in 63% yield. The conversion of (-)-1a to leaf-closing substance 2a and an attempted approach to naturally occurring compounds 1b and 2b have been also described. (c) 2006 Elsevier Ltd. All rights reserved.
Green aldose isomerisation: 2-C-methyl-1,4-lactones from the reaction of Amadori ketoses with calcium hydroxide
作者:David J. Hotchkiss、Raquel Soengas、Kathrine V. Booth、Alexander C. Weymouth-Wilson、Vanessa Eastwick-Field、George W.J. Fleet
DOI:10.1016/j.tetlet.2006.11.137
日期:2007.1
Saccharinic acids, branched 2-C-methyl-aldonic acids, may be accessed via a green procedure from aldoses by sequential conversion to an Amadori ketose and treatment with calcium hydroxide; D-galactose and D-glucose are converted to 2-C-methyl-D-lyxono-1,4-lactone (with a small amount of 2-C-methyl-D-xylono-1,4-lactone) and 2-C-methyl-D-ribono-1,4-lactone. Inversion of configuration at C-4 of the branched lactones allows access to 2-C-methyl-L-ribono-1,4-lactone and 2-C-methyl-L-lyxono-1,4-lactone, respectively. D-Xylose affords 2-C-methyl-D-threono-1,4-lactone and 2-C-methyl-D-erythrono-1,4-lactone, whereas L-arabinose, under similar conditions, gave the enantioiners 2-C-methyl-L-lactone-1,4-lactone and 2-C-methyl-L-erythrono-1,4-lactone. (c) 2006 Published by Elsevier Ltd.
Enantioselective synthesis of both diastereomers, including the α-alkoxy-β-hydroxy-β-methyl(phenyl) units, by chiral tin(II) Lewis acid-mediated
作者:Shū Kobayashi、Mineko Horibe、Yumi Saito
DOI:10.1016/s0040-4020(01)85531-9
日期:——
Diastereo- and enantioselective synthesis of both diastereomers, including the alpha-alkoxy-beta-hydroxy-beta-methyl(phenyl) units, was performed by using chiral tin(II) Lewis acid-mediated asymmetric aldol reactions of a-alkoxy silyl enol ethers with alpha-ketoesters. (S)-1-Propyl-2-[(1,2,3,4-tetrahydroisoquinolinyl))methyl]pyrrolidine (13), a new type of chiral diamine, was found to be effective as a chiral source in these reactions and also in the reactions of 2-(t-butyldimethylsiloxy)-1-ethylthio-1-(trimethylsiloxy)ethene (9) with aldehydes for the synthesis of optically active syn-a,p-dihydroxy thioester derivatives. (-)-2-C-Methyl-D-erythrono-1,4-lactone and (+)-2-C-methyl-L-threono-1,4-lactone were synthesized by using these reactions.
Concise synthesis of enantiopure erythro-saccharinic acid lactone and potassium (2R,3R)-2,3,4-trihydroxy-2-methylbutanoate
作者:Alexandros E. Koumbis、Apostolos D. Kaitaidis、Stefanos S. Kotoulas
DOI:10.1016/j.tetlet.2006.09.156
日期:2006.11
A short and efficient approach was applied to the total synthesis of erythro-saccharinic acid lactone and the leaf-closing substance potassium (2R,3R)-2,3,4-trihydroxy-2-methylbutanoate from a 2-C-hydroxymethyl-D-erythrose derivative, using a combined strategy. (c) 2006 Elsevier Ltd. All rights reserved.
An Efficient Preparation of 2-<i>C</i>-Methyl-<scp>d</scp>-Erythritol 4-Phosphoric Acid and Its Derivatives
作者:Klaus Kis、Juraithip Wungsintaweekul、Wolfgang Eisenreich、Meinhart H. Zenk、Adelbert Bacher