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5-Hydroxy-3-methyl-2-pentenoic acid

Chloro ulfonyl isocyanate and isoprene in ether give 5-hydroxy-3-methyl-2-pentenoic acid lactone (4-methyl-5,6-dihydro-2-pyrone, XII-98) and 5-amino-3-methyl-3-pentenoic acid lactam (4-methyl-3,6-dihydro-2-pyridone, XII-99) by hydrolysis of intermediate N-sulfochlorides that were not isolated ... [Pg.617]

A more useful way of reducing esters to ethers is a two-step procedure applied to the reduction of lactones to cyclic ethers. First the lactone is treated with diisobutylaluminum hydride in toluene at —78°, and the product - a lactol - is subjected to the action of triethylsilane and boron trifluoride etherate at —20° to —70°. y-Phenyl-y-butyrolactone was thus transformed to 2-phenyltetrahydrofuran in 75% yield, and 5-lactone of 3-methyl-5-phenyl-5-hydroxy-2-pentenoic acid to 4-methyl-2-phenyl-2,3-dihydropyran in 72% yield [1034]. [Pg.150]

The volatiles produced by sugar degradation can make an important contribution to flavour. Pyrolysis of glucose at 300 °C allowed 56 compounds to be identified, the main product being l,4 3,6-dianhydroglucopyranose.567 More than 100 volatiles were separated when glucose was heated at 250 °C for 30 min in air or in nitrogen 4-hydroxy-2-pentenoic acid lactone, 1-(2-furyl)propane-l,2-dione, and 3-methyl-cyclopentane-1,2-dione were identified as new products.568... [Pg.150]

H)-Furanone, 5-methyl- 4-hydroxy-3-pentenoic acid lactone a-angelica lactone ... [Pg.1079]

Aminodeoxy sugars are biochemically interesting due to their efficiency as enzyme inhibitors as well as their potential anti-HIV activity. Double deprotonation of 153 and subsequent treatment with acrolein affords 164 as the major diastereomer (92 8). Alkaline hydrolysis of this crude mixture provides (7 )-3-hydroxy-4-pentenoic acid (165) with 83.5% ee. This is easily enhanced by resolution via the (5)-l-phenethylammonium salt, so that 165 can in fact be obtained with 99% ee. lodolactonization of 165 generates the second stereogenic center and provides the furanone skeleton 166, isolated with 97.8% de. Depending on the sequence of transformations chosen, 166 can be converted either to methyl (3i ,47 )-5-amino-2,5-... [Pg.161]

VII-D-2. 5-Methyl-3H-furan-2-one (4-Hydroxy-3-pentenoic Acid y-Lactone, a-Angelica Lactone)... [Pg.847]

In an attempt to elaborate50 a synthetic access to DL-garosamine [126, 3-deoxy-4-C-methyl-3-(methylamino)-DL-arabinopyranose], the 1,5-lactone of 5-hydroxy-4-methyl-3-pentenoic acid (124) was oxy-aminated, to yield 2,3-dideoxy -C-methyl-3-p-toluenesulfonamido-DL-enyfhro-pentono-l,5-lactone (125). Introduction of a hydroxyl... [Pg.23]

The iodolactonization of 2-substituted 4-pentenoic acids with. V-iodosuccinimide or iodine in the presence of tetraisopropoxytitanium gives the /-lactone with high 1,3-cij selectivity39b. Thus, when 2-hydroxy-2-methyl-4-pentenoic acid (3) in dichloromethane is treated with one equivalent of tetraisopropoxytitanium prior to the addition of iodine, a cisjtrans selectivity of 96 4 is obtained39b. [Pg.234]

C6H10O2 2-methyl-3-pentenoic acid 37674-63-8 472.15 41.215 1,2 7905 C6H10O3 cis-2-hydroxy-1 -cyclopentanecarboxylic acid 17502-28-2 459.55 40.012 2... [Pg.441]

C6H10O2 trans-2-methyl-2-pentenoic acid 16957-70-3 487.15 42.651 1,2 7907 C6H10O3 methyl 3-hydroxy-2-methylenebutyrate 18020-65-0 459.55 40.012 2... [Pg.441]

Acetamide, 2-amino-N-(2-hydroxy-1 -methyl-2-phenylethyl)-N-methyl-, [R-(R, R )]-, 4-Pentenoic acid, 2-amino-, (R)- and 4-Pentenoic acid, 2-[[(1,1-dimethylethoxy)carbonyl]amino]-, (R)-)... [Pg.57]

A xylan extracted from the holocellulose present in the stalks of Nicotiana tabacum has been purified by ion-exchange chromatography. The results of methylation analysis, partial hydrolysis with acid, and enzymic hydrolysis indicated that the xylan is composed of a straight chain of approximately 100 /S-(l -> 4)-linked D-xylopyranosyl residues. Curie point-g.l.c. of the xylan yielded 2-furaldehyde, which is probably formed via 3-deoxy-D- /ycero-pent-2-ulose. Another major product was identified as 3-hydroxy-2-penteno-1,5-lactone (21) by high-resolution m.s. this lactone has also been prepared by pyrolysis of a hexuronic acid-containing xylan from beech. Since the tobacco-stalk xylan contains no acidic components, the lactone (21) must arise by... [Pg.233]

Sato, T., K. Tajima, and T. Fujisawa Diastereoselective synthesis of erythro- and threo-2-hydroxy-3-methyl-4-pentenoic acids by the ester enolate Claisen rearrangement of 2-butenyl 2-hydroxy acetate. Tetrahedron Letters 24, 729 (1983). [Pg.217]

Fujino, A. and Sugai, T. (2008) Chemoenzymatic approach to enantiomerically pine (R)-3-hydroxy-3-methyl-4-pentenoic acid ester and its application to a formal total synthesis of taurospongin A. Adv. Synth. Catal., 350,1712-1716. [Pg.228]

A total hydrolysis of verrucarin J (36) yielded as one of three products the lactone of 5-hydroxy-3-methyl-cfs-2-pentenoic acid. Therefore, it was anticipated that a CIS double bond would be present between the centers C(2 ) and C(3 ) in the side chain of verrucarin J (36) (Fetz et aL, 1965). This conclusion... [Pg.76]

ASYMMETRIC CATALYTIC GLYOXYLATE-ENE REACTION METHYL (2R)>2 HYDROXY-4-PHENYL-4 PENTENOATE (Benzenabutanoic acid, a-hydroxy-y-methylene, methyl ester, (R)-)... [Pg.8]

Annual Volume 71 contains 30 checked and edited experimental procedures that illustrate important new synthetic methods or describe the preparation of particularly useful chemicals. This compilation begins with procedures exemplifying three important methods for preparing enantiomerically pure substances by asymmetric catalysis. The preparation of (R)-(-)-METHYL 3-HYDROXYBUTANOATE details the convenient preparation of a BINAP-ruthenium catalyst that is broadly useful for the asymmetric reduction of p-ketoesters. Catalysis of the carbonyl ene reaction by a chiral Lewis acid, in this case a binapthol-derived titanium catalyst, is illustrated in the preparation of METHYL (2R)-2-HYDROXY-4-PHENYL-4-PENTENOATE. The enantiomerically pure diamines, (1 R,2R)-(+)- AND (1S,2S)-(-)-1,2-DIPHENYL-1,2-ETHYLENEDIAMINE, are useful for a variety of asymmetric transformations hydrogenations, Michael additions, osmylations, epoxidations, allylations, aldol condensations and Diels-Alder reactions. Promotion of the Diels-Alder reaction with a diaminoalane derived from the (S,S)-diamine is demonstrated in the synthesis of (1S,endo)-3-(BICYCLO[2.2.1]HEPT-5-EN-2-YLCARBONYL)-2-OXAZOLIDINONE. [Pg.266]


See other pages where 5-Hydroxy-3-methyl-2-pentenoic acid is mentioned: [Pg.239]    [Pg.597]    [Pg.604]    [Pg.19]    [Pg.379]    [Pg.443]    [Pg.453]    [Pg.1061]    [Pg.263]    [Pg.889]    [Pg.894]    [Pg.719]    [Pg.724]    [Pg.239]    [Pg.597]    [Pg.604]    [Pg.234]    [Pg.533]   


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3- Hydroxy-4-pentenoate

3- Pentenoic acid

4-Methyl-3-pentenoic acid

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