13861-97-7Relevant academic research and scientific papers
2-Siloxy-Substituted Methyl Cyclopropanecarboxylates as Building Blocks in Synthesis: Efficient One-Pot Conversion to γ-Butyrolactones
Grimm, Erich L.,Reissig, Hans-Urlich
, p. 242 - 244 (1985)
A high-yield one-pot transformation to the easily available 2-siloxy-substituted methyl cyclopropanecarboxylates 3 to γ-butyrolactones 5 is described.According to the regioselective preparation of 3, isomeric lactones 5 can be synthesized without problems.Modified procedures delivering α-deuterated or side-chain functionalized lactones are disclosed.
A new and short enantioselective synthesis of (R)-pantolactone
Upadhya,Gurunath,Sudalai
, p. 2899 - 2904 (1999)
Dihydro-4,4-dimethyl-2(3H)-furanone 6, the key intermediate to (R)-pantolactone 2, has been synthesized in two steps via the radical cyclization of bromoether 5. Silyl enol ether 7, prepared from 6, on Sharpless asymmetric dihydroxylation gave (R)-pantolactone 2 in moderate yield and excellent enantioselectivity.
SELECTIVE OXIDATION OF A PRIMARY HYDROXYL IN THE PRESENCE OF SECONDARY ONE
Tomioka, Hiroki,Takai, Kazuhiko,Oshima, Koichiro,Nozaki, Hitosi
, p. 1605 - 1608 (1981)
RuCl2(PPH3)3-benzene system has been found to be highly effective for the title selective oxidation providing 10-hydroxyundecanal in 89percent yield from 1,10-undecanediol.
Structural and stereochemical requirements of the spiroketal group of hippuristanol for antiproliferative activity
Li, Wei,Dang, Yongjun,Liu, Jun O.,Yu, Biao
, p. 3112 - 3115 (2010)
Hippuristanol is a natural product that has recently been shown to inhibit eukaryotic translation initiation and tumor cell proliferation. To investigate the structure and activity relationship of hippuristanol, we synthesized a series of analogs by expan
Α-hydroxycarboxylic acid or its oligomer by treatment with hydrogen at high temperature and high pressure water or hydroxy butyrolactone derivative γ - furanone derivative
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Paragraph 0027; 0046-0050; 0053; 0054, (2017/11/11)
PROBLEM TO BE SOLVED: To provide a method of manufacturing a furanone derivative or a γ-butyrolactone derivative by a high temperature high pressures water treatment of hydroxy carboxylic acid having a hydrogen atom and a hydroxyl group at α-position or its oligomer.SOLUTION: A method of manufacturing a furanone derivative or a γ-butyrolactone derivative uses hydroxy carboxylic acid having a hydrogen atom and a hydroxyl group at α-position or its oligomer as a raw material, and mixes the raw material solution and high temperature high pressure water, and conducts a reaction at a temperature in a range of 200°C to 500°C to synthesize the furanone derivative or the γ-butyrolactone derivative. A novel synthesis method of the furanone derivative or the γ-butyrolactone derivative using the hydroxy carboxylic acid having a hydrogen atom and a hydroxyl group at α-position or its oligomer as the raw material can be provided and it can synthesize with one step reaction, has high yield, and is easy to separate and purify.
Synthesis of Lactones via C-H Functionalization of Nonactivated C(sp3)-H Bonds
Richers, Johannes,Heilmann, Michael,Drees, Markus,Tiefenbacher, Konrad
, p. 6472 - 6475 (2016/12/23)
An electron-deficient amide is utilized as a directing group to functionalize nonactivated C(sp3)-H bonds through radical 1,5-hydrogen abstraction. The γ-bromoamides formed are subsequently converted to γ-lactones under mild conditions. The method described is not limited to tertiary and secondary positions but also allows functionalization of primary nonactivated sp3-hybridized positions in a one-pot sequence. In addition, the broad functional group tolerance renders this method suitable for the late-stage introduction of γ-lactones into complex carbon frameworks.
Design and synthesis of potent hydroxyethylamine (HEA) BACE-1 inhibitors carrying prime side 4,5,6,7-tetrahydrobenzazole and 4,5,6,7- tetrahydropyridinoazole templates
Sund, Christian,Belda, Oscar,Borkakoti, Neera,Lindberg, Jimmy,Derbyshire, Dean,Vrang, Lotta,Hamelink, Elizabeth,Hgren, Cathrine,Woestenenk, Esmeralda,Wikstroem, Kristina,Eneroth, Anders,Lindstroem, Erik,Kalayanov, Genadiy
, p. 6721 - 6727,7 (2012/12/12)
A set of low molecular weight compounds containing a hydroxyethylamine (HEA) core structure with different prime side alkyl substituted 4,5,6,7-tetrahydrobenzazoles and one 4,5,6,7-tetrahydropyridinoazole was synthesized. Striking differences were observed on potencies in the BACE-1 enzymatic and cellular assays depending on the nature of the heteroatoms in the bicyclic ring, from the low active compound 4 to inhibitor 6, displaying BACE-1 IC50 values of 44 nM (enzyme assay) and 65 nM (cell-based assay).
Diverting non-haem iron catalysed aliphatic C-H hydroxylations towards desaturations
Bigi, Marinus A.,Reed, Sean A.,White, M. Christina
scheme or table, p. 216 - 222 (2011/12/16)
Carboxylate-ligated, non-haem iron enzymes demonstrate the capacity for catalysing such remarkable processes as hydroxylations, chlorinations and desaturations of inert, aliphatic C-H bonds. A key to functional diversity is the enzymes' ability to divert fleeting radicals towards different types of functionalization using active site and/or substrate modifications. We report that a non-haem iron hydroxylase catalyst [Fe(PDP)] can also be diverted to catalytic, mixed hydroxylase/desaturase activity with aliphatic C-H bonds. Using a taxane-based radical trap that rearranges under Fe(PDP) oxidation to furnish a nortaxane skeleton, we provide the first direct evidence for a substrate radical using this class of stereoretentive hydroxylation catalysts. Hydroxylation and desaturation proceed by means of a short-lived radical that diverges in a substrate-dependent manner in the presence of carboxylic acids. The novel biomimetic reactivity displayed by this small molecule catalyst is harnessed to diversify natural product derivatives as well as interrogate their biosynthetic pathways.
Direct lactonization of alkenols via osmium tetroxide-mediated oxidative cleavage
Schomaker, Jennifer M.,Travis, Benjamin R.,Borhan, Babak
, p. 3089 - 3092 (2007/10/03)
(Matrix presented) A highly efficient, mild, and simple protocol is presented for the tandem OsO4-mediated oxidative cleavage/oxidative lactonization of alkenols to lactones. The protocol couples the OsO 4-catalyzed oxidative cleavage of olefins with Oxone as the co-oxidant with the direct oxidation of aldehydes in alcoholic solvents to their corresponding esters.
Spirolactones from Dirhodium(II)-Catalyzed Diazo Decomposition with Regioselective Carbon-Hydrogen Insertion
Doyle, Michael P.,Dyatkin, Alexey B.
, p. 3035 - 3038 (2007/10/02)
Dirhodium(II) caprolactamate, Rh2(cap)4, catalyzes diazo decomposition of cycloalkylmethyl diazoacetates which form spirolactones in moderate to high yield by insertion into a tertiary carbon-hydrogen bond.Similar results are obtained with diazoacetates derived from tetrahydropyran-2-methanol and tetrahydrofurfuryl alcohol but not from cyclopropylmethanol.With tetrahydrofuran-3-ylmethyl diazoacetate, Rh2(cap)4 catalysis promotes δ-lactone formation via insertion into the oxygen-activated secondary C-H bond instead of γ-lactone formation by carbene insertion into the unactivated tertiary C-H bond.However, when both 1,5- and 1,6-positions are activated for insertion by adjacent oxygen atoms, as in (2,2-dimethyl-1,3-dioxolan-4-yl)methyl diazoacetate, five-membered ring formation occurs exclusively in Rh2(cap)4-catalyzed reactions, whereas use of dirhodium(II) acetate leads to both insertion products.
