1.2- Propanediol reduction

Diaminopropane Processes. 1,2-Propylenediamine can be produced by the reductive amination of propylene oxide (142), 1,2-propylene glycol [57-55-6] (143), or monoisopropanolamine [78-96-6] (144). 1,3-Propanediol [504-63-2] can be used to make 1,3-diaminopropane (143). Various propaneamines are produced by reducing the appropriate acrylonitrile—amine adducts (145—147). Polypropaneamines can be obtained by the oligomerization of 1,3-diaminopropane (148,149). 

Porco s route to (—)-kinamycin C (3) began with 2,5-dihydroxybenzaldehyde (38), which was elaborated to the enone 35 by the sequence shown in Scheme 3.6. Regioselective bromination [25] followed by methylation and reduction of the aldehyde function afforded the primary alcohol 39. The alcohol 39 was dearomatized by treatment with bis(acetoxy)iodobenzene, to afford the quinone monoketal 41. Transketalization with 1,3-propanediol followed by silylation of the primary alcohol generated the silyl ether 42 in 72 % yield over three steps. 

Kometani et al. [71] reported that baker s yeast catalyzed the asymmetric reduction of acetol to (i )-1,2-propanediol with ethanol as the energy source. The enzyme involved in the reaction was an NADH-dependent reductase, and NADH required for the reduction was supplied by ethanol oxidizing enzyme(s) in the yeast. When washed cells of baker s yeast were incubated with 10 mg ml of acetol in an ethanol solution with aeration, (k)-1,2-propanediol was formed almost stoichiometrically with an optical purity of 98.2% e. e. 

Etbyl-l,5-propanediol or Ethyltrimetbylene-glycol, HO.Ol2.CH(CaHB)-CH mw 104.15 liq, bp 124-7°(l6 mm Hg). Prepd by the lithium aluminum hydride reduction of 2-ethyl diethylmalonate... 

If 1 1 complexes are formed (1) in the ground state, then two types of photoreactions will occur parallel to each other, that of the bare and that of the complexed solute, each in its own type of cage. Mixed alcohol/ alkane systems, for example, show an indication of preformed solute-solvent complexes as evidenced by the picosecond experiments of Wang and Eisenthal80 81 on DMABN. Planar model systems like the indolines 3 and 5 (Sec. II.A.l) indicate that an additional channel opens for the B state in alcoholic solvents which increases the nonradiative decay path. This can explain the observed reduction of the fluorescence quantum yield in jirotic solvents about 0.1 in the aprotic polar solvent n-butyl chloride, about 0.01 in 1,2-propanediol, and about 0.001 in water.228... 

Propanediol is produced either from the reductive hydration of acrolein (Degussa-DuPont process), or through reductive carbonylation of ethylene oxide (Shell process), or through fermentation of glucose via glycerol (DuPont-Genencor process). 

Catalytic reduction and/or fermentation to produce 1,3-propanediol, a polymer with applications in the textile sector and a key feedstock for production of the renewable polymer Sorona produced by Du Pont... 

A new synthetic approach to polycyclic aromatic compounds has been developed based on double Suzuki coupling of polycyclic aromatic hydrocarbon bis(boronic acid) derivatives with o-bromoaryl aldehydes to furnish aryl dialdehydes. These are then converted to larger polycyclic aromatic ring systems by either (a) conversion to diolefins by Wittig reaction followed by photocyclization, or (b) reductive cyclization with trifluoromethanesulfonic acid and 1,3-propanediol (Eq. (12)) [30]. 

Recently, a series of studies of the stereoselective reduction of 1,3-diketones has been reported which expands upon this methodology. When 1,3-diphenyl-1,3-propanedione was reduced with three equivalents of NaBH4 in the presence of (S,S)-15,THFA,and ethanol in CHCI3 at -20°C, (S,S)- 1,3-diphenyl- 1,3-propanediol was obtained quantitatively in 97% ee (Scheme 9) [54], The anti syn ratio of the product was 84 16. Diketones with electron-donating and electron-withdrawing substituents on their phenyl rings were also reduced with high enanti-oselectivity and diastereoselectivity. 

Zeolites have also been successfully applied in the reverse reaction, i.e. the hydrolysis of ethers to alcohols. A relevant example is the splitting of bis(3-hydroxypropyl)ether. This compound is a by-product in 1,3-propanediol synthesis, which can be performed by hydration of acrolein and reduction of 3-hydroxypropanal (23). In the hydrolysis of bis(3-hydroxypropyl)ether, a 20 weight % aqueous solution of the ether is passed over a ZSM-5 catalyst at 240°C ... 

Reduction of the compound 112 with LiAlH4 afforded 2-(3-cyclooctenyl)-1,3-propanediol 113 which was oxydized by reaction with ozone to the acid 114. 

The aminodiol 745, obtained from 2-amino-1,3-propanediol by two sequential reductive alkylations with 2,4-dimethoxybenzaldehyde and benzaldehyde, reacted with 3-chloro-2-(chloromethyl)prop-l-ene to give dioxocin 683 in 46% yield <2006JOC413>. Similar formation of dioxocins was observed when 3-chloro-2-(chloromethyl)prop-l-ene... 

Schutz, H., Radler, F. (1984a). Anaerobic reduction of glycerol to propanediol-1,3 by Lactobacillus brevis and Lactobacillus buchneri. Syst. Appl. Microbiol., 5, 169-178. 

Production of some C3 and C4 chirals such as EP, CPD, GLD, propanediol, 4-chloro-3-hydroxybutyrate is also being carried out or has been reported by other means such as chiral metal catalysts [2], reduction using microorganisms [3] or enzymatic resolution of suitable derivatives [4], A comparison of these methods can be found in [1]. 

Phenmenthol monomalonates 1.20 are transformed by LDA into dilithiated anions, which also suffer diastereoselective alkylations on their least hindered face [166, 1008, 1034], After UAIH4 reduction, enantioenriched 2,2-dialkyl-l,3-propanediols are obtained. Alternatively, Curtius reaction followed by hydrolysis gives rise to nonracemic a-substituted aminoacids (Figure 5.16). The most interesting selectivities are observed when R and R are PhCH-j and Me. The highly stereoselective alkylation of the menthyl monoester of (1R, 2R)-cydopen-tanedicarboxylic add by methaliyl bromide is the first step of the total synthesis of (-)-ptaquilosin [1035]. 

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