Phenyl butyrolactone

Fig. 2.4. Preparative chromatographic resolution of 5 g of )/-phenyl-)>-butyrolactone on 480 g of CTA I (column 5 cm x 60 cm). [Reproduced from Helv. Chim. Acta 70 1569 (1987) by permission of Verlag Helvetica Chimica Acta, A.G.]...

Metlio -6 niethyl.phthalid 18 1 303. /J-Oxy- -phenyl-butyrolacton 18, 20. a-Oxy.y-phenyl-batyrolacton 18, 20. /J-Oxy- E-phenyl butyioIactaD 18 n 12. K-Oxy- -phenyl-butyroIactOn 18 1 303. 

Oxy-a oder y)-methyl-y Oder Qt)-phenyl butyrolacton-y-oarboDsaure 18, 526. -Oxy->/(oder )-methyJ-o (oder yj-pbeny l-butjfrolacton-y-carbonsatire 18, 526. 2.5>Dimei oa7-3.4 methylendioxy-zimt aldehyd 191 715, II 236. 

The reaction of a halide with 2-butene-1,4-diol (104) affords the aldehyde 105, which is converted into the 4-substituted 2-hydroxytetrahydrofuran 106, and oxidized to the 3-aryl-7-butyrolactone 107[94], Asymmetric arylation of the cyclic acetal 108 with phenyl triflate[95] using Pd-BINAP afforded 109, which was converted into the 3-phenyllactone 110 in 72% ee[96]. Addition of a molecular sieve (MS3A) shows a favorable effect on this arylation. The reaction of the 3-siloxycyclopentene 111 with an alkenyl iodide affords the. silyl... 

The potential for use of chiral natural materials such as cellulose for separation of enantiomers has long been recognized, but development of efficient materials occurred relatively recently. Several acylated derivatives of cellulose are effective chiral stationary phases. Benzoate esters and aryl carbamates are particularly useful. These materials are commercially available on a silica support and imder the trademark Chiralcel. Figure 2.4 shows the resolution of y-phenyl-y-butyrolactone with the use of acetylated cellulose as the adsorbent material. 

Polymers containing pendant carbamate functional groups can be prepared by the reaction of phenyl isocyanate with poly(vinyl alcohol) in homogeneous dimethylsulfoxide solutions using a tri-ethylamine catalyst. These modified polymers are soluble in dimethyl sulfoxide, dimethylacetamide, dimethylformamide and formic acid but are insoluble in water, methanol and xylene. Above about 50% degree of substitution, the polymers are also soluble in acetic acid and butyrolactone. The modified polymers contain aromatic, C = 0, NH and CN bands in the infrared and show a diminished OH absorption. Similar results were noted in the NMR spectroscopy. These modified polymers show a lower specific and intrinsic viscosity in DMSO solutions than does the unmodified poly(vinyl alcohol) and this viscosity decreases as the degree of substitution increases. 

B. D. Andresen, F. T. Davis, J. L. Templeton, R. H. Hammer, H. L. Panzik, Synthesis and Characterizaiton of a/p/za-Phenyl-garona-Butyrolactone, a Metabolite of Glutethi-mide, Phenobarbital and Primidone, in Human Urine , Res. Commun. Chem. Pathol. Pharmacol. 1976, f J, 21 - 30. 

A parallel study [94] was performed by the same authors on the retention of model compounds (tryptophan, erythro- and t/ireo-P-methyltryptophan, A-carbobenzyloxy-tryptophan, A-(3,5-dinitro-2-pyridyl)-tryptophan, l-[5-chloro-2-(methylamino) phenyl]-l,2,3,4-tetrahydroisoquinoline, and y-phenyl-y-butyrolactone) on a ristocetin A-based CSP, using the three RP, POM, and NP elution systems. Also, in this case, the natural logarithms of the retention factors (In k) of the investigated compounds depended linearly on the inverse of temperature (1 /T). 

Elimination of hydrogen bromide from a-bromo-y-butyrolactone with triethylamine, 46,22 Epichlorohydrin, 46, 24 Ether, /-butyl phenyl, id, 89 /j-Ethoxyphenyl isothiocyanate, 46, 21 Ethyl acetoacetate, 46, 82 Ethyl benzoyloxy cyanoacetates, 46, 38 Ethyl y-BROMOBUTYRATE, 46, 42 Ethyl 2-biomocyclopentane acetate, 46, 44... 

Examples of catalysis involving concerted cyclic proton tremsfer in water have recently been reported in the hydrolysis of N-phenyl-iminotetrahydrofuran (Cunningham and Schmir, 1966, 1967). There is no effect of HjPO, HCO3, and CH3COOH on the rate of hydrolysis, but the type of product obtained, butyrolactone or 7-hydroxybutyranilide is dependent on their concentration. The following scheme was proposed [equation (8)]. 

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]. 

A similar spiro-fused starting material was prepared to study the thermolysis of a 1,3-dioxane analog. As found for the dithia compound (cf. Section 8.11.6.3.1), a carbene-derived dimer was formed as the major detectible product (20%) <2002TL1927>. Other products, such as tricycle 185, have been identified in subsequent studies <2004CJC1769>. However, phenyl substitution at G-4 provided completely different thermolysis products, probably via formation of an open-chain bis-radical. Thus, 3-phenyl-7-butyrolactone and, after CO2 extrusion, phenylcyclo-propane are the major reaction products (Scheme 58) <2002CJC1187>. 

Asymmetric hydroalkoxycarbonylation of a-methylstyrene is also examined, leading to 3-phenyl-butanoic acid, the //< r///< /-product. The highest ee is at best 60% for this substrate.When an allylic alcohol is treated with a chiral Pd complex under GO, cyclohydrocarbonylation takes place to give the corresponding 7-butyrolactone in an asymmetric manner (Equation (6)). Similarly, chiral -lactones and other lactams can also be synthesized. 

Butyrolactones, 58, 82 Butyromtnle, 2-benzyl-2-phenyl-, 55, 94 Butyronitrile, 4-bromo-2,2-diphenyl-, 55, 94 Butyromtnle, 2-tert butoxycarbonyl-methyl-2-phenyl-, 55, 94 Butyromtnle, 3-methyl-2-phenyl-, 55, 102 Butyromtnle, 3-methyl-2-phenyl-2-vinyl-,... 

Bamford-Stevens reaction of the tosylhydrazones of the readily available tetrahydrofuran-3-ones provides a useful synthesis of 2,3-dihydrofurans which may be dehydrogenated to furans with 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (66CJC1083). Tetrahydrofuran-2-ones (y-butyrolactones) may be alkylated in the 3-position with LDA and an alkyl halide. The products on reaction with phenyl selenylchloride and LDA, and subsequent oxidation, yield 3-alkylfuran-2(5//)-ones reducible with DIBAL to furans (75JOC542). 

R1 = R2 = H) gave the triazolo[l,5-a]pyrimidines (125), but with 124 (R1 = R2 = Me) afforded the dioxo derivative 126, and with a-cyano- y-butyrolactones (127) or 2-amino-3-ethoxycarbonyl-5,6-dihydro-4//-thiopyran (129) gave the triazolopyrimidines 128 and 130, respectively (81JHC1287). Treatment of 4-ethoxymethylene-2-phenyl-5(4//)-oxazolone (131) with 5-amino-3-methylthio-l//-1,2,4-triazoles gave the triazolo[l,5-a]pyrimidi-none 132 and the [4,3-a] isomer 133 (93H955) (Scheme 24). 

In addition, there are [5 -> 3 + 2] fragmentations leading to acyclic products that result from the original fragments by rearrangement. Examples are 5-phenyl-l,2,3,4-thiatriazole (50) and related compounds with three ring heteroatoms and an exocyclic double bond (51),THF (52), y-butyrolactone (53), y-thiobutyrolactone (54), pyrroles (8,61), pyrrolidine (55), furans (56, 58), pyrazole (62), and isoxazoles (11, 63,64). Most of these molecules are thermally rather stable and their decomposition requires drastic conditions. 

A new Y solvolysis scale has been developed for benzylic species with extensive charge delocalization, based upon the solvolyses of some benzhydryl bromides and /-butyl(2-naphthyl)methyl bromides.39 Chlorides have negative salt effects on the ionization of benzhydryl bromide in 7-butyrolactone.40 The X-ray structure of the dimerization product of l,8-bis(dhnethylammonio)-4-naphthyl(phenyl)methyl carbocation has been determined it appears to be formed via a 4n + 2n-cycloaddition mechanism 41... 

FIGURE 6 Effect of mobile phase composition on the resolution of enantiomers of different racemates in normal phase HPLC on antibiotic CSPs. (a) First ( ) and second ( ) eluted enantiomers of y-phenyl-y-butyrolactone and first ( ) and second (O) eluted enantiomers of 4-phenyl-2-methoxy-6-oxo-2,4,5,6-tetrahydropyridine-3-carbonitrile on Chirobiotic T column and (b) first ( ) and second (O) eluted enantiomers of mephenytoin on Chirobiotic V column. (From Refs. 1 and 21.)... 

Butyrolactones are used in the synthesis of cyclopentenone derivatives 362 364). 3-Phenyl-1-propanol can be produced from styrene and formaldehyde 366). 

While the reaction of 73 is stereoselective, it has been shown that the photodecarboxylation of simple y-butyrolactones gives product selectivities that depend on the nature of the substrate. From the phenyl-substituted lactones 77-80, only 79 gives rise to phenyl cyclopropane in low yields (Scheme 2.18) [49]. Diphenyl-substituted lactones cis-80 and trans-80 give identical mixtures of cis- and trans- 1,2-diphenylcy-clopropane in 50-60% yield. Cyano-lactone 81 was the most efficient of the set, giving cis- and trans-l-cyano-2-phenylcyclopropanes in 44% and 48% yields. The simple trend that surfaces from this small number of examples (i.e., 73 and 77-81) is that radical-stabilizing substituents alpha to the lactone carbonyl may be important for the reaction to take place. 

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