87894-65-3Relevant academic research and scientific papers
A gas-liquid chromatographic method for steric analysis of 2-hydroxy, 3-hydroxy, and 2,3-dihydroxy acids
Zhang, Lian-Ying,Hamberg, Mats
, p. 151 - 161 (2007/10/02)
A method was developed for assignment of the absolute configuration of oxylipin-derived 2-hydroxy acids, 3-hydroxy acids and 2,3-dihydroxy acids.The monohydroxy acids were converted into diastereomeric N-(propionoxyacyl)-L-phenylalanine-methyl ester (PAP) derivatives by coupling to the methyl ester of L-phenylalanine followed by propionylation, whereas 2,3-dihydroxy acids were derivatized by treatment with L-phenylalanine methyl ester followed by acetone and perchloric acid, to afford diastereomeric N-(2,3-isopropylidenedioxyacyl)-L-phenylalanine methyl ester (IAP) derivatives.The PAP and IAP derivatives were readily resolved by capillary gas-liquid chromatography.In addition, the method described allowed steric analysis of 3-hydroxy-3-methylheptanoic acid, a branched chain hydroxy acid derived from the prostaglandin analogue, misoprostol. - Keywords: Hydroxy acid; Phenylalanine; Steric analysis; Gas-liquid chromatography
Biosynthetic Studies on Tajixanthone and Shamixanthone, Polyketide Hemiterpenoid Metabolites of Aspergillus variecolor
Ahmed, Salman A.,Bardshiri, Esfandiar,McIntyre, C. Rupert,Simpson, Thomas J.
, p. 249 - 274 (2007/10/02)
The biosynthesis of tajixanthone and related metabolites of Aspergillus variecolor has been studied by incorporation experiments with simple and advanced precursors labelled with the stable isotopes 13C, 2H and 18O.Tajixanthone is shown to be derived through ring cleavage of an octaketide-derived anthraquinone with introduction of two dimethylallyl moieties.From the results of isotopic labelling experiments and chemical studies on model compounds, an overall biosynthetic pathway is proposed and information on the mechanisms of interconversion of proposed intermediates is obtained.
SYNTHESIS OF SUBSTITUTED BENZENOIDS AND BIPHENYLS VIA DIELS-ALDER CYCLOADDITION OF 6-METHOXY-2-PYRONES
Ahmed, Salman A.,Bardshiri, Esfandiar,Simpson, Thomas J.
, p. 1595 - 1596 (2007/10/02)
A convenient synthesis of substituted 6-methoxy-2-pyrones from alkyl and aryl esters is described.These pyrones undergo Diels-Alder reactions with acetylenic dienophiles to provide an efficient route to polysubstituted benzoates, phthalates and biphenyls.
A Convenient Synthesis of Isotopically Labelled Anthraquinones, Chrysophanol, Islandicin, and Emodin. Incorporation of Chrysophanol into Tajixanthone in Aspergillus variecolor
Ahmed, Salman A.,Bardshiri, Esfandiar,Simpson, Thomas J.
, p. 883 - 884 (2007/10/02)
Cycloaddition reactions of labelled 6-methoxy-3-methyl-2-pyrone (1) with naphthoquinones provide the common fungal anthraquinones, chrysophanol (2), islandicin (3), and emodin (4) suitably labelled for biosynthetic studies, as demonstrated by synthesis and incorporation of chrysophanol into the xanthone metabolite, tajixanthone (17) in Aspergillus variecolor.
Studies on a Synthesis of (RS)-Mevalonic Acid Lactone
Bardshiri, Esfandiar,Simpson, Thomas J.,Scott, A. Ian,Shishido, Kozo
, p. 1765 - 1767 (2007/10/02)
Full details of a high yielding synthesis of mevalonic acid lactone (1) which is of particular value in the preparation of 3- and/or 3'-labelled compounds are described.The key step, conversion of 3-hydroxy-3-methylpentane-1,5-dioic acid (3) into 3-hydroxy-3-methylpentane-1,5-dioic anhydride (4) using acetic anhydride, has been fully investigated, and an additional method using acetyl chloride and triethylamine is described.
Reinvestigation of a Synthesis of (R,S)-Mevalonolactone
Lewer, Paul,MacMillan, Jake
, p. 1417 - 1420 (2007/10/02)
An n.m.r. study of the reaction of 3-hydroxy-3-methylpentane-1,5-dioic acid (5) with excess of acetic anhydride is described.It has shown that 3-hydroxy-3-methylpentane-1,5-dioic acid anhydride (2), previously described by Scott and Shishido as an intermediate in their synthesis of mevalonolactone, is formed only transiently, along with 3-acetoxy-3-methylpentane-1,5-dioic acid (6).Both intermediates eventually give 3-acetoxy-3-methylpentane-1,5-dioic acid anhydride (3).To obtain (R,S)-mevalonolactone, sodium borohydride reduction of 3-hydroxy-3-methylpentane-1,5-dioic acid anhydride (2), prepared from the diacid (5) and N,N-dicyclohexylcarbodi-imide, is shown to be better than reduction of 3-acetoxy-3-methylpentane-1,5-dioic acid anhydride (3).
