Propyn-l-ol

2-Propyn-l-ol is a moderately toxic substance cansing depression of the Central nervous system and irritation of the eyes and skin. 

LD50 value, oral (rats) 70 mg/kg LD50 value, oral (guinea pigs) 60 mg/kg 

Flammable liquid flash point (open cup) 33°C (91°F) vapor forms explosive mixtures with air LEE and UEL data not available. 2-Propyn-l-ol may react violently with strong oxidizers. It ignites when mixed with phosphorus pentoxide. 

Because of the presence of a triple bond, an acetylenic hydrogen, and the primary hydroxyl group, this compound is highly active and undergoes reactions of substitution, hydrogenation, and oxidation types to 

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Whereas the Rh2(OAc)4-catalyzed addition of diazoalkanes to propargyl alcohols readily gives the insertion of the carbene into the 0-H bond, with only a small amoimt of cyclopropenation of the resulting propargylic ether [54] the 2-diazopropane 59 reacts at 0 °C with l,l-diphenyl-2-propyn-l-ol 62a in dichloromethane and exclusively gives, after 10 h of reaction, only the adduct 63a isolated in 75% yield and corresponding to the regioselective 1,3-dipolar cycloaddition of the 2-diazopropane to the alkyne C - C bond (Scheme 15). 

F. B. Growcock and V. R. Lopp. The inhibition of steel corrosion in hydrochloric acid with 3-phenyl-2-propyn-l-ol. Corrosion Sci, 28(4) 397-410,1988. 

Trimethylsilyl-2-propyn-l-o1 was obtained from Petrarch Systems, Inc. and used as received. Alternatively, it can be prepared by the silylation of 2-propyn-l-ol ... 

Silylformylation of 1-alkynes is not affected by the presence of small amounts (2 to 3 molar equiv.) of water or methanol in the reaction mixture. The corresponding products are formed in yields similar to the reaction without these additives.This information implies that the silylformylation of alkyne is not affected by the presence of a protic functional group, such as hydroxy and amino groups in alkyne. In fact, 2-propyn-l-ol 54 smoothly gives 55, in which the hydroxy group remains intact (Equation (15)). (Z)-Selectivity in 55 is drastically improved by the reaction in the absence of EtsN or by use of Rh2(pfb)4 as the catalyst. The Rh complex is known to work as an active catalyst for alcoholysis of hydrosilane." " In particular, since Rh2(pfb)4 shows high activity for alcoholysis of EtsSiH in the absence of it is quite notable that the product derived from silane alcoholysis is not detected at... 

To a flask containing 12.4 gm (0.037 mole) of l-(a-naphthyl)-l,3-diphenyl-2-propyn-l-ol in 50 ml of dry ether is added 2.0 gm (0.015 mole) of phosphorus trichloride in 10 ml of ether. The solution is stirred at room temperature for 2 hr, filtered, the solid washed with dry ether, and dried to afford 6.5 gm (50 %),... 

DeMaster E.G., Dahlseid, T. and Redfern, B. (1994) Comparative oxidation of 2-propyn-l-ol with other low molecular weight unsaturated and saturated primary alcohols by bovine liver catalase in vitro. Chem. Res. Toxicol., 7 (3), 414-419. 

The suspension 1s cooled to 20°C on 1ce and then 800 mL of 1.4 M aqueous sulfuric acid is cautiously added over 0.75 hr so that the temperature remains below 45°C. The resulting solution is stirred for 5 min and then 600 mL of ether is added. Both phases are transferred to a 4-L separatory funnel and the layers are separated. The aqueous phase is extracted twice with 400-mL portions of ether and all ether layers are individually washed in series with two 1-L portions of water and once with 800 mL of saturated sodium chloride solution. The combined organic extracts are dried over magnesium sulfate and concentrated by rotary evaporation. The yellow-brown residue is purified by short path distillation to afford 82-86 g (91-94 yield) of 3-trimethylsilyl-2-propyn-l-ol as a clear, colorless liquid (Note 7), bp 76°C (20 mm) (Note 8). 

Reduction of 3-trimethyls1lyl-2-propyn-l-ol exemplifies the problem of stereoselectivity in hydride reduction of acetylenic alcohols to E-allyl alcohols.4 Early reports5 that lithium aluminum hydride stereoselectively reduced acetylenic alcohols gave way to closer scrutiny which revealed a striking solvent dependence of the stereochemistry. Specifically, the... 

Its Potassium salt, deliquescent crysts Mercury salt, pltlts, dec >240°and Silver salt, voluminous ppt, explodes violently when heated have been prepd in addn to many other derivs (Ref 1) l,l-Dimethyl-2-propyn-l-nitrite 3,3-Dimethyl-l-propyn-3-ol (called Nitrite Ester of 2-Methyl-3-hutyn-2-ol in CA), HCiC.C(CH3)2.ONO mw 113.11, N 12.38% liq, hp 80-82° at 750mm press nD 1.3926 at 20° was prepd when NOCl ether were added to a stirred soln of 3 methyl-l-butyn-3-oI (parent compd)... 

Several syntheses for the preparation of 1,4-oxazino[3,2-/>][l, 4]oxazine derivatives are known. The reaction of 2-propyn-l-ols (287) with 2-aminoalcohols (288) and mercury(II) chloride gives cis-l,4-oxazino[3,2-6][l,4]oxazine derivatives (289) (Equation (46)) <86CB887>. 

Furanes. Hydromagnesiation of 3-trimethylsilyl-2-propyne-l-ol (1) (11, 163) followed by reaction with an aldehyde or ketone provides E-3-lrimethylsilyl-2-alkcne-l,4-diols (2). These are converted into 3-trimethylsilyl-2,5-dihydrofurancs (3) on dehydration... 

Reduction of propargyl alcohols. 3-Trimethylsilyl-2-propyne-l-ol (1), prepared as shown from propargyl alcohol, is reduced stereospecifically by SMEAH to (E)-3-trimethylsilyl-2-propene-1-ol (2). Reductions of propargyl alcohols with LiAIH4 are less rraws-selective. 

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