A Methyl-y-valerolactone

Ring-opening polymerization of a-methyl-substituted medium-size lactones, a-methyl-y-valerolactone and a-methyl-c-caprolactone, proceeded by using lipase CA catalyst in bulk [82]. As to (R)- and (S)-3-methyl-4-oxa-6-hexa-nolides (MOHELs), lipase PC induced the polymerization of both isomers. The apparent initial rate of the S-isomer was seven times larger than that of the R-isomer, indicating that the enantioselective polymerization of MOHEL took place through lipase catalysis [83]. 

Levulinic acid is obtained by hydrolysis of cellulose-containing biomass. R D is actively conducted at DuPont Co. to employ levulinic acid for the synthesis of pyr-rolidones (solvents and surfactants), a-methylene-y-valerolactone [monomer for the preparation of polymers similar to poly(methyl methacrylate)], and levulinic acid esters (fuel additives) [26]. 

A similar rearrangement has been observ ed in the treatment of y-methyl-y-valerolactone with potassium cyanide whereby y-methyl-yS-cyanovaleric acid is formed instead of the expected y-cyano acid. ... 

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... 

Acrylic monomers can be derived from biomass (53). An early synthesis of a-methylene-y-valerolactone involves two steps (54,55). The first step is the carboxylation of y-butyrolactone with methyl methoxymagnesium carbonate Stiles reagent) to produce the acid. Next, the acid is briefly treated with a mixture of aqueous formaldehyde and diethylamine, followed by a separate treatment of the crude product with sodium acetate in acetic acid. The first step requires 6-7 h and affords almost quantitative yields, whereas the second step can be accomplished in less than 30 min but with yields of only 50%. 

Another example is the carbonylation of allyl carbinol under the conditions of the Reppe reaction [525], yielding a-methyl-y-butyrolactone plus S-valerolactone. 

HL 8-Membered lactone 8-OL 8-Octanolide HDL 16-Hexadecanolide MVL a-Methyl-5-valerolactone UDL 11-Undecanolide aMCL a-Methyl-e-caprolactone 8-DL 5-Decalactone y-BL y-Butyrolactone y-CL y-Caprolactone y-VL y-Valerolactone 5-VL 6-Valerolactone ... 

Five membered, unsubstituted, lactone 7-butyrolactone (y-BL) was polymerised by PPL or PCL [16, 73] into small oligomers with a degree of polymerisation (DP) of 8-11. In the Pseudomonas sp, lipase catalysed polymerisation of y-VL and y-CL, less than 10% conversion was observed at 60 °C for 480 hours [75]. Unsubstituted and substituted six membered lactone 6-valerolactone (6-VL) [26, 69, 79-80] and a-methyl-6-valerolactone (MVL) [81] were polymerised using Rhizopus japonicus lipase, CCL, PFL, PPL and CAL enzymes. For unsubstituted 5-VL, the reactions were run for 5-10 days and the highest molecular weights obtained were in the range of 2,000 Da. CAL catalysed polymerisation of a-methyl-6-valerolactone yielded polyester with a M of up to 11,400 at 60 °C in 24 hours. 

Reduction of lactones leads to cyclic bemiacetals of aldehydes. With a stoichiometric amount of lithium aluminum hydride in tetrahydrofuran at —10° to —15° and using the inverse technique, y-valerolactone was converted in 58% yield to 2-hydroxy-5-methyl tetrahydrofuran, and a-methyl-5-caprolac-tone in 64.5-84% yield to 3,6-dimethyl-2-hydroxytetrahydropyran [1028]. Also diisobutylaluminum hydride in tetrahydrofuran solutions at subzero temperatures afforded high yields of lactols from lactones [7024]. 

There are other reactions which have been found to yield oxetanes but have not been developed as synthetic methods. The thermolysis and photolysis of y-methyl-y-peroxy-valerolactone gives 2,2-dimethyloxetane, presumably by way of a diradical intermediate (equation 87). This is the same type of intermediate involved in pyrolysis of the oxetane at a much higher temperature (71CC1299). Somewhat related are photochemical syntheses... 

Alkylation of the 2-methyl-2-oxazoline (base/electrophile) results in homologated 2-oxazolines. A second alkylation sequence proceeds with asymmetric induction and results in the formation of highly substituted chiral 2-alkyl alkanoic acids. Use of ethylene oxide as the electrophile in this process allows for the formation of chiral a-substituted y-butyrolactones and a-substituted 7-valerolactones with good stereoselectivity (60-80% ee eq 3). ... 

The powerful Lewis acidity of a titanium(IV) salt is demonstrated in its room-temperature catalysis of the reaction of an aminonitrile with a lactone, d-valerolactone or its 6-methyl homologue. y-Butyrolactone gave poor yields [3638], Tin(IV) chloride also promotes cyclization of aminobenzonitriles with j8-keto esters to give the medicinally useful 4-aminoquinolines [3871]. 

The absolute configuration at C-2 of C was elucidated by identifying the (-f- )-/3-methyl-y-carboxy-y-valerolactone (CVII) with one of the two possible forms (threo or erythro). The cyanhydrin of ( )-j3-methyllevu-linic acid (CXVI) gave on hydrolysis two lactones (+ )-lactone A, CXVI (mp 151°-152° p-bromophenacyl ester, mp 86°-88°) and lactone B, CXVII (mp 65°-67° p-bromophenacyl ester, mp 105°-106°). Lactone B... 

By using a modification of a reaction discovered by Traube and Lehmann (61,62), Leuchs, Giua, and Brewster (63) synthesized 4-hydroxy-proline from a-carbethoxy-a, 5-dichloro-y-valerolactone from which Leuchs and Brewster (64) prepared Z-hydroxyproline by resolution with the aid of quinine. On methylation of a sample of Z-hydroxyproline thus prepared, Kiing (65) obtained a mixture of optically active betaines which he separated by fractional crystallization into a levorotatory betaine identical with betonicine and a dextrorotatory betaine identical with turicine. Betonicine is, therefore, the methyl betaine of 4-hydroxyhygrinic acid (XXIV). Betonicine and turicine possess different solubilities and can be separated... 

Burke discloses a two-step process for the conversion of butadiene to adipic acid at high yields [156]. The first step is the hydrocarboxylation of butadiene to form 3-pentenoic acid. The second step is the hydrocarboxylation of 3-pentenoic acid with carbon monoxide and water in the presence of a rhodium-containing catalyst, an iodide promoter, and certain inert solvents such as methylene chloride. The first reaction step gives also a significant by-product of y-valerolactone and a minor by-product of a-methyl-7-butyrolactone. These lactones can be converted to adipic acid by modified catalyst compositions [157-159]. In a related work, pentenic acids or esters are used as the starting intermediates for conversion to adipic acid [160-166]. 

PPG-3 methyl ether PPG-2 methyl ether acetate n-Propyl bromide Propylene glycol ethyl ether acetate propylene glycol laurate SD alcohol 1 SD alcohol 3-A SD alcohol 3-C SD alcohol 12-A SD alcohol 23-A SD alcohol 30 Tetrahydrofuran Toluene 1,1,1-Trichloroethane Triglycol monomethyl ether Tri hexyl citrate Trimethyl citrate y-Valerolactone VM P naphtha Xylene p-Xylene... 

These metabolites were generated during digestion and intestinal absorption as a result of phase II enzymes and were converted into glucuronidated and sulfated metabolites as well as methylated metabolites. The procyanidins, which were not absorbed in the small intestine, passed into the large intestine where they were degraded by the colonic microflora into phenolic acids, which could be absorbed into the circulatory system and subjected to phase II metabolism prior to excretion. Serra et al. [34] used a colonic fermentation model with rat colonic microflora and reported that the phen-ylacetic acid and its hydroxylated forms were the main fermentation products, and hydroxy-y-valerolactone was specifically from procyanidin compounds. 

Draw the structure of each of the following compounds (a) /3-butyrolactone (b) /3-valerolactone (c) S-valerolactone (d) /3-propiolactam (e) a-methyl-S-valerolactam (f) iV-methyl-y-butyrolactam. 

Raney-Ni alloy added in small portions during 1.5 hrs. to a well-stirred soln. of -(2-oxocyclopentyl)butyric acid in aq. NaOH, and stirring continued 7 hrs. at room temp. -methyl-y,<5-cyclopentano-5-valerolactone (Y 98.9%) added at ca. 60° to polyphosphoric acid, and heated 5.5 hrs. at the temp, with occasional swirling under anhydrous conditions -> 4-methylbicyclo[3.3.0]-id 1.5-octen-2-one (Y 95.5%). Overall Y ca. 66%. F. e. s. T. M. Jacob and S. Dev, J. Indian Ghem. Soc. 36, 429 (1959). 

---