7-Valerolactone hydrogenation

Levulinic acid. Hydrogenation of levulinic acid resulting in the reduction of the ketone moiety leads to 4-hydroxy pentanoic acid. This acid can cyclize to form y-valerolactone (GVL) which is a useful industrial solvent. A 94% yield of GVL was obtained with a Raney nickel catalyst, and a hydrogen pressure of 5 MPa at a temperature of 100-150... 

Figure 20. Simultaneous enantiomer separation of various classes of compounds ( Schurig test mixture 184) on CP-Cyclodextrin-/3-2,3,6-M-19 (permethylatcd /3-cyclodextrin in OV-1701) [25 m x 0.25 mm (i.d.) column, 70°C for 5 min followed by 3cC/miu, 0.65 bar hydrogen]143. 1+2 2,6,6-trimethylbicy-clo[3.1.1]hept-2-ene (x-pinene), 3 ( + )-(lJR)-//ms-2,6,6-trimethylbicyclo[3.1. l]heptane (pinane), 4 (-)-(lS )-fra/M-pinanc. 5 (-)-(lS)-fw-pinane, 6 ( + )-(l/J)-cw-pinane, 7 + 8 2,3-butancdiol. 9 meso-2,3-butanediol, 10 + 11 tetrahydro-5-methyl-2-furanone (y-valerolactone). 12 + 13 1-phenylethanaminc. 14 + 15 1-phenylethanol, 16 + 17 2-ethylhexanoic acid.

Acetylanthracene, 30,1 Acetylation, of 2- -acetylphenylhydro-quinone, 34, 1 of hydrogen sulfide, 31, 105 a-Acetyl-7-butyrolactone, 31, 74 Acetyl chloride, 30, 1 (X-ACETYL-5-CHLORO-7-VALEROLACTONE, 31, 1... 

Figure 8 Guest-dependent polymorphism in CA inclusion crystals with (a) acetophenone, (b) y-valerolactone, (c) ethynylbenzene, (d) 2-fluoropropiophenone, (e) m-chloroaniline, (f) water (Form I), (g) water (Form II), (h) 3-methylcyclohexanone, (i) acetic acid, (j) m-fluoroaniline, (k) 1,2,3-trimethylbenzene, and (1) acrylonitrile. Hydrogen atoms are omitted for clarity. Carbon, nitrogen and oxygen atoms are represented by open, gray and tilled circles, respectively. 

More advantageous is the use of solids acids and especially bifunctional catalysts, exhibiting acid sites for hydrolysis in combination with a metal (Rh, Pt, Ru, and Ni) for hydrogenation, which can be used, in appropriate solvents, for the direct conversion of cellulose into value-added chemicals (e.g. sorbitol, mannitol, ethylene glycol, hydroxymethylfurfural, 2,5-dimethyltetrahydrofuran, levulinic acid, valerolactone, and isosorbide) [33 36]. 

Scheme 10.3 Hydrogenation pathway of y-buty-y-valerolactone leading to the formation of 4-methyl-1 -octanol.

In the reactions of /1-propiolactone, y-valerolactone, and d-valerolactone no products could be isolated due to tarring,Lactides react with sulfur tetrafluoride, without ring opening, to give tetrafluorodioxanes and higher fluorinated dioxanes." 6-Chloro-4-hydroxycoumarin dimerizes upon reaction with sulfur tetrafluoride/hydrogen fluoride to a fluorinated spiro compound. - ... 

Related work includes investigations of carbon formation during hydrogenation of C5 hydrocarbons catalyzed by nickel and palladium (5P) interactions of N2O with a hydrotalcite-derived multimetallic mixed oxide catalysts (60,61) changes in mass of solid oxides (62) methanol sorption in Nafion-117 (proton-exchange) membranes (63) vanadyl pyrophosphate catalysts for butane oxidation (64-66) and deactivation/regeneration of a Rb0 c/Si02 catalyst for methylene valerolactone synthesis (67). 

Many of the methods listed for the preparation of hydroxy acids (Table 47) have been used to prepare lactones directly. Reduction of levulinic acid, CHjCOCHjCHjCOjH, by sodium and alcohol or by catalytic hydrogenation over Raney nickel leads to "y-valerolactone. S-Captolactone is prepared in a similar manner from y-acetobutytic acid. Other S-lactones have been formed by catalytic hydrogenation of the corresponding aldehydo... 

By using chiral Ru complexes such as BINAP-Ru(II) or DIOP-Ru(II), 3-substituted glutaric anhydrides are enantioselectively hydrogenated to give 3-substituted d-valerolactone in up to 60% e.e. [201]. 

A procedure for preparation of /8-methyl-8-valerolactone from 3-methylpentane-1,5-dioP shows that copper chromite is an effective catalyst for dehydrogenation. Presumably the reaction proceeds through the aldehyde and hemiacetal. The evolution of hydrogen is nearly quantitative and the yield of lactone high. 

In contrast to the previous case, the presence of the hydrogen instead of the phenyl above the plane of the ring does not change the optical purity , but the replacement of the methoxy by hydroxyl reduces remarkably the optical purity . These facts point towards an initial bonding of the alkyl lithium to the nitrogen and oxygen, which places the nucleophile below the ring plane. The chiral oxazoline was used by Meyers and Nihelich also in asymmetric synthesis of 2-alkylbutyrolactone and by Meyers and Whitten in the synthesis of 3-alkyl valerolactone . ... 

In branched-chain fatty acids the hydrogen on a tertiary carbon atom can be replaced by hydroxyl by means of alkaline permanganate solution e.g., 2-hydroxy-2-methylpropionic acid, HO—C(CH3)2—C02H, is obtained from isobutyric acid, and 4-methyl-y-valerolactone is obtained from 4-methylvaleric acid.227... 

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