2417-14-3Relevant academic research and scientific papers
Studies on paraherquamide biosynthesis: synthesis of deuterium-labeled 7-hydroxy-pre-paraherquamide, a putative precursor of paraherquamides A, E, and F
Sommer, Konrad,Williams, Robert M.
experimental part, p. 3246 - 3260 (2009/09/06)
The stereocontrolled, asymmetric synthesis of triply deuterium-labeled 7-hydroxy-pre-paraherquamide (27) was accomplished, employing a diastereoselective intramolecular SN2′ cyclization strategy. The deuterium-labeled substrate was interrogated in a precursor incorporation experiment in the paraherquamide-producing organism Penicillium fellutanum. The isolated sample of paraherquamide A revealed incorporation of one of the two geminal deuterons of the CD2-group at C-12 exclusively. The lack of signals for the second deuteron of the CD2-group at C-12 and for the CH2D-group (C-22/C-23) suggests that this substrate suffered an unexpectedly selective catabolic degradation and metabolic re-incorporation of deuterium thus casting doubt on the proposed biosynthetic intermediacy of 27. Consideration of alternative biosynthetic pathways, including oxidation of the indole C-6 position prior to hydroxylation at C-7 or oxidative spiro-contraction of pre-paraherquamide prior to construction of the dioxepin is discussed. The synthesis of 27 also provides for a concise, asymmetric stereocontrolled synthesis of an advanced intermediate that will be potentially useful in the synthesis of paraherquamides E and F.
Construction of the "left domain" of haplophytine
Nicolaou,Majumder, Utpal,Roche, Stephane Philippe,Chen, David Y.-K.
, p. 4715 - 4718 (2008/02/08)
(Chemical Equation Presented) Left of the middle: Synthesis of the "left" structural domain (2) of haplophytine (1) features a stereoselective construction of its sterically congested carbon-carbon bond (C9′-C15) and an efficient cascade sequence involvin
Use of indole derivative for dyeing keratin materials, tinctorial compositions, new compounds and dyeing process
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, (2008/06/13)
Process for dyeing keratin fibers by using derivatives of formula: STR1 where: R1 =H, lower alkyl or SiR11 R12 R13 ; R2 and R3, which may be identical or different, =H, alkyl, carboxyl, alkoxycarbonyl or --COOSiR11 R12 R13 ; R4 to R7, which may be identical or different, =H or an O--Z group, where Z=H, C1 -C20 alkyl, aralkyl, formyl, C2 -C20 acyl, C3 -C20 alkenyl, --SiR11 R12 R13, --P(O)(OR8)2, R8 OSO2 ; or a heterocycle which may contain a P(O)(OR8) or CR9 R10 group; with the reservation that at least two of R4 to R7 denotes OZ or form a ring, and that at least one of R4 or R7 represents OZ; R8 and R9 =H, lower alkyl; R10 =alkoxy, mono- or dialkylamino; R11, R12 and R13, which may be identical or different, are alkyl groups; or their alkali metal, alkaline-earth metal, ammonium and amine salts.
