4295-92-5Relevant articles and documents
Improved procedure for the preparation of cis-2,4-dimethylglutaranhydride
Saicic, Radomir N.
, p. 2559 - 2562 (2006)
Addition of 2.5 mol% DBU to a mixture of isomeric 2,4-dimethylglutaric anhydrides in ethyl acetate promotes crystallization-induced transformation, affording the pure cis -2,4-dimethylglutaric anhydride in 87% yield. Copyright Taylor & Francis Group, LLC.
Stereoelectronic Effects: Perlin Effects in Thiane-Derived Compounds
Basche, Luis,Jung, Sebastian T.,Luy, Burkhard,Podlech, Joachim,Reinsperger, Tony
, (2020/04/15)
Stereoelectronic effects in thianes and thiane-derived sulfoxides, sulfones, sulfilimines, and sulfoximines were investigated by measuring 1JC,H coupling constants and by identification of normal and reversed Perlin effects, i.e., of differences in the coupling constants for equatorial and axial C–H bonds in the methylene groups of six-membered rings. The Perlin effects were correlated with results from natural bond orbital (NBO) analyses. NMR experiments were performed with conformationally restricted dimethyl- or tert-butyl-substituted derivatives, while the parent compounds were used for calculations. It turned out that the coupling constants are not only strongly influenced by stereoelectronic interactions with antiperiplanar C–H, C–C, C–O, and C–N bonds, but by the s character of the respective C–H bonds' carbon orbital as well.
The Catalytic Alkylative Desymmetrization of Anhydrides in a Formal Synthesis of Ionomycin
Oberg, Kevin M.,Cochran, Brian M.,Cook, Matthew J.,Rovis, Tomislav
supporting information, p. 4343 - 4350 (2018/06/08)
The catalytic desymmetrization of anhydrides with zinc reagents provides access to deoxypolypropionate and polypropionate synthons. A synthesis of ionomycin was pursued in which three of the four fragments were assembled using this methodology. Two of the strategies (enol silane/oxocarbenium coupling and reductive cyclization) were not successful at installing the C23 stereocenter, but this stereochemical issue was overcome through a reduction/S N 2 approach. In addition to the synthesis of a protected diastereomer of ionomycin, the synthesis of a C17-C32 fragment constitutes a formal total synthesis.
Regioselective photochemical rearrangement of N-mesyloxylactams
Pichette, Simon,Aubert-Nicol, Samuel,Lessard, Jean,Spino, Claude
supporting information; experimental part, p. 1328 - 1335 (2012/04/05)
N-Mesyloxylactams can undergo ring contraction either by C-3 (usually observed) or C-5 migration. C-5 migration can occur when the C-3 migration product possesses ring strain, but it does not usually compete with C-3 migration. The greater preference for C-3 migration is due to the carbonyl oxygen atom, which greatly stabilizes the intermediate. Studies of the photochemical rearrangement of N-mesyloxylactams showed that the lone pair of the carbonyl oxygen atom, and not the degree of the substitution atthe migrating carbon atoms, is the governing factor in the regioselectivity of the reaction. Copyright
Accessing the structural diversity of pyridone alkaloids: Concise total synthesis of rac-citridone A
Fotiadou, Anna D.,Zografos, Alexandros L.
supporting information; experimental part, p. 4592 - 4595 (2011/10/17)
A unique route to the structural diversity of pyridone alkaloids is described based on the concept of a common synthetic strategy. Three different core structure analogues corresponding to akanthomycin, septoriamycin A, and citridone A have been prepared by using a highly selective and novel carbocyclization reaction.
Microwave-assisted selective protection of glutaraldehyde and its symmetrical derivatives as monoacetals and -thioacetals
Flink, Heli,Putkonen, Tiina,Sipos, Attila,Jokela, Reija
experimental part, p. 887 - 890 (2010/03/24)
Six monoprotected acetals and -thioacetals of glutaradehyde and its symmetrical dimethyl derivatives were synthesized. Microwave-assisted heating proved to be a substantially more selective method for monoprotection than conventional heating. All reactions were efficient and only traces of diprotected material were formed.
Formal synthesis of Abyssomicin C
Couladouros, Elias A.,Bouzas, Emmanuel A.,Magos, Alexandros D.
, p. 5272 - 5279 (2007/10/03)
An alternative strategy towards Abyssomicin C (1) is described. The key ene-diene intermediate is synthesized via a Kishi type coupling of an E/Z mixture of triene-iodide 7 and a suitably functionalized derivative of 2,4-dimethylglutaric acid. A final in
Chemoenzymatic synthesis of the C10-C23 segment of dictyostatin
Prusov, Evgeny,Roehm, Hartmut,Maier, Martin E.
, p. 1025 - 1028 (2007/10/03)
Employing enzymatic desymmetrization and resolution, respectively, the two aldehydes 8 and 20 were prepared. The precursor to aldehyde 8, meso-2,4-dimethylglutaric anhydride 3, could be obtained by base treatment of the diastereomeric mixture. Aldehyde 8
Synthetic routes to the stereoisomers of 2,4-dimethylpentane-1,5-diol derivatives
Mas, Gemma,González, Llu?sa,Vilarrasa, Jaume
, p. 8805 - 8809 (2007/10/03)
Five different routes to every stereoisomer of non-symmetric derivatives of 2,4-dimethylpentanedioic acid and/or of O-monoprotected 2,4-dimethylpentane- 1,5-diols, which are common building blocks for the total synthesis of many polypropionates, have been investigated. Alkylation of the lithium enolate of N-propanoylpseudoephedrine turned out to be the most appropriate method, in connection with the synthesis of fragment C1-C5 of amphidinolide K.
Toward a total synthesis of okilactomycin. 1. A direct, enantiocontrolled route to the western sector
Paquette, Leo A.,Boulet, Serge L.
, p. 888 - 894 (2007/10/03)
A synthesis of the western half of the macrocyclic ring framework of the antitumor antibiotic okilactomycin is described. The strategy employed rests on an efficient synthesis of meso-2,4-dimethylglutaric anhydride and ensuing resolution via reaction with (S)-(-)-α-methylbenzylamine, diborane reduction, and selective crystallization. Following acid-catalyzed cyclization to (2S,4R)-2,4-dimethyl-δ-valerolactone, an acyclic stereocontrol strategy was adopted to achieve chain lengthening with appropriate incorporation of functionality. The sensitive aldehyde 2 was further homologated to β-keto ester 17 in a model reaction sequence performed to simulate its ultimate projected coupling to 3.
