1,3-Propane diol

The reaction of diacetylene with propane-1,3-diol gives 2-(prop-2-ynyl)-l,3-dioxane (39), 2-(propa-l,2-dienyl)-l,3-dioxane (40), and 2-(prop-l-ynyl)-l,3-dioxane (41) (74ZOR953). 

Unsaturated substituents of dioxolanes 36-38 and dioxanes 39-41 are prone to prototropic isomerization under the reaction conditions. According to IR spectroscopy, the isomer ratio in the reaction mixture depends on the temperature and duration of the experiment. However, in all cases, isomers with terminal acetylenic (36, 39) or allenic (37, 40) groups prevail. An attempt to displace the equilibrium toward the formation of disubstituted acetylene 41 by carrying out the reaction at a higher temperature (140°C) was unsuccessful From the reaction mixture, the diacetal of acetoacetaldehyde 42, formed via addition of propane-1,3-diol to unsaturated substituents of 1,3-dioxanes 39-41, was isolated (74ZOR953). 

Five hundred milligrams of the diacetate of (dl)-reg.-1-p-nitrophenyl-2-dichloroacetamido-propane-1,3-diol is dissolved in a mixture consisting of 25 cc of acetone and an equal volume of 0.2 N sodium hydroxide solution at 0°C and the mixture allowed to stand for one hour. The reaction mixture is neutralized with hydrochloric acid and evaporated under reduced pressure to dryness. The residue is extracted with several portions of hot ethylene dichloride, the extracts concentrated and then cooled to obtain the crystalline (dl)-reg.-l-p-nitrophenyl-2-dichloroacetamidopropane-1,3-diol MP 171°C. 

Another commonly used bactericide is 2-bromo-2-nitro-propane-1,3-diol. 

The first example of a stable 1,1-bidentate Lewis acid based on boron and zirconium has been reported [35]. The synthesis of 22 is outlined in Scheme 7.12. Treatment of hex-l-yne with HBBr2 Me2S followed by conversion of the dibromoboronic ester to the corresponding alkenyl boronic acid and esterification with propane-1,3-diol provided the alkenyl boronic ester. Hydrozirconation of this compound with 3 equivalents of the Schwartz reagent, Cp2Zr(H)Cl [57], afforded the desired product 22 in 86% yield. 

Interestingly, the most potent analog 58 contains both the more rigid isophthalate linker and the longer propane-1,3-diol linker [65]. 

Microorganisms have also been developed to produce alternative products, such as lactic acid [65], propane-1,3-diol [67], 3-hydroxypropionic acid [68], butane-2,3-diol [69] and numerous other intermediates. For instance, bacteria such as the Clostridium acetobutylicum ferment free sugars to C4 oxygenates such as butyric acid or butanol. They form the C4 oxygenates by Aldol condensation of the acetaldehyde intermediates. The Weizmann process exploits this property to ferment starch feedstock anaerobically at 37 °C to produce a mixture of w-butanol, acetone and ethanol in a volume ratio of 70 25 5 [3],... 

Classical examples of industrial biotechnology include the manufacture of ethanol, lactic acid, citric acid, and glutamic acid. The share of renewables in the feedstock of the chemical industry is expected to increase substantially in the years to come [2-4], A newcomer here is propane-1,3-diol (DuPont/Tate Lyle), with the start-up of industrial fermentation foreseen within one year. 

A palladium phosphine complex [e.g., BCPE = l,2-bis(l,5-cyclooctylenephos-phino)ethane] was also reported to produce propanediols and n-propanol from glycerol at 443 K under 6 MPa CO/H2 atmosphere in acidic conditions, n-Propanol is the dominant product, while a slight preference for the formation of propane-1,3-diol is seen in the diol fraction. Reactions were performed at different temperatures in the range 413-448 K. Since acrolein was monitored at high temperature, a reaction network was proposed following a sequential dehydration/hydrogenation pathway [20]. 

Iterative two-directional chain elongation enables rapid construction of 1,3-polyols (Scheme 23). For example, the polyol substructure that appears in the oxopolyene macrolide (+)-roxaticin is available in nine steps from propane-1,3-diol upon three iterations of double carbonyl allylation [286]. Notably, high levels of catalyst-directed stereoselectivity are observed (For selected examples of catalyst directed diastereoselectivity, see [289-296]). Analogous 1,3-polyol syntheses via iterative homologation in one direction also are reported [297]. 

Glycinamide hydrochloride Tris (tris(hydroxymethyl)-amino methan 2-amino-2-hydroxy methyl-propane-1.3-diol Trizma)... 

While two studies of the bacterial mutagenicity of 2,2-bis(bromomethyl)propane-1,3-diol gave negative results, a positive result was obtained in Salmonella typhimurium TA100 when liver S9 from Aroelor-indueed male Syrian hamsters was used at a concentration of 30% (v/v). In other strains of S. typhimurium and in experiments with rat liver S9, no mutagenie activity was detected. 

The formation of intermediate fluorosulfites also appears to be characteristic of the reactions of 1,3- and 1.4-diols however, these compounds were not isolated. The reaction of propane-1,3-diol, butane-1,3-diol and butane-1,4-diol with sulfur tetrafluoride gives, respectively, 3-fluoro-propan-l-ol, 3-fluorobutan-l-ol and 4-fluorobutan-l-ol.59... 

CH2C12 (10 mL) containing propane-1,3-diol (3.04 g, 40 mmol) and pyridine (6.94 g, 88 mmol) was added dropwise to a stirred solution of triflic anhydride (24.8 g, 88 mmol) in cold (0°C) CH2C12 (20 mL), The mixture was stirred at 0LC for 30 min then filtered through a 4-cm bed of silica gel to remove pyridinium triflate. The filtrate was concentrated in vacuo at rt to provide a viscous, orange liquid, presumed to be... 

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