3- BUTYN-2-OL, 2-METHYL

Beilstein Handbook Reference) AI3-23121 BRN 0635746 1-Butyn-3-ol, 3-methyl- 3-Butyn-2-ol, 2-methyl- Carbavane Dimethylacetylenecarbinol Dimethylacetylenylcarbinol Dimelhylethynylcarbinol Dimethylethynylmethanol a.a-Dimethylpropargyl alcohol EINECS 204-070-5 ... 

CYCLOHEXEN-l-ONE. Importantly, only 1.6 equivalents of Ag20 are required for efficient coupling. The final preparation in this series illustrates the hydrosilation of racemic 3-butyn-2-ol catalyzed by a phosphine based platinum(O) catalyst. The resultant racemic (E)-vinylsilane is then resolved with a commercially available lipase and subjected to a Johnson ortho ester Claisen rearrangement to afford [3R- AND 3S-]-(4E)-METHYL... 

Treatment of 4-methylbenzenesulfenyl chloride with (+ )-(/ )-3-butyn-2-ol gives directly optically active l-(4-methyl)phenylsulfinyl-l,2-butadiene (15) with almost complete asymmetric induction at both newly created stereogenic centers109. 

Many monoterpenes are desired fragrances in perfumery and flavors in food. They are produced on a larger scale from acetone (C3) and ethyne (acetylene C2) involving repetitive synthetic steps (Fig. 5). Initially, acetone is ethynylated by acetylene in the presence of a base (sodium hydroxide, amines with sodium carbonate) yielding 3-butyn-2-ol (C5) which is partially hydrogenated in the presence of deactivated catalysts (Lindlar catalysts) to 2-methyl-3-buten-2-ol. This can be converted to the key intermediate 6-methyl-5-hepten-2-one (Cg) via two pathways, either by transetherification with methylpropenylether and subsequent oxa-CoPE rearrangement, or by transesterification with methyl acetoacetate and subsequent Carroll decarboxylation. 

Butyn-l-ol Biacetyl Methyl acrylate l-Chloro-2-methyl-l-propene a-3-Chloro-2-buten-l-ol / -3-Chloro-2-buten-l-ol... 

Enantiomerically pure allenylzinc and indium reagents are readily available through oxidative transmetallation of transient allenylpalladium intermediates derived from sulfonic esters of (/ )- or (5)-3-butyn-2-ol derivatives, such as 250. When these transmetaUations are conducted in the presence of aldehydes, anti homopropargylic alcohol adducts 251 are formed with high diastereoselectivity (Scheme 10.49). The preference for anti over syn adducts can be assigned to an unfavorable eclipsing interaction between the methyl group of allenyl moiety and the... 

Besides Y- and MFI-type zeolites, other zeoHtes such as BETA [107,108] and clinoptilolite [109] were also loaded with Cu via SSIE. H-BETA was reacted with increasing amounts of CuCl, finally resulting in a complete disappearance of the acid OH groups as evidenced by IR. It was shown that two kinds of Cu(I) sites exist. The equilibria for CO adsorption on these sites were involved in the car-bonylation of alcohols which, however, required the simultaneous presence of residual adjacent acid OH groups. Copper could be introduced by SSIE into natural clinoptilolite to an extent which was comparable to that of conventional exchange [109]. The zeolite obtained by solid-state reaction was successfully employed in the catalytic 3-methyl-3-butyn-2-ol decomposition. 

Methylethylldene)bis(4,l-phenyleneoxy-4,1-phenylene-sulf onyl-4,1-phenyleneoxy-3,1-phenylene)]bis[2-methyl-3-butyn-2-ol] IV... 

Dimethyl-3,5-octadiyne-2,7-diol (1, Scheme 4) is obtained by CuClj-promoted oxidativ< coupling of 2-methyL3-butyn-2-ol H. A. Stansbury, Jr. and W. R. Proops, J. Org. Chem. 27 321 (1962). Preparation of 2-methyl-3-butyn-2 oI Org. Synth. 3 320 (1955). 

A similar approach had been reported earlier by Bestmann and coworkers" in their synthesis of hexadeuteriated leukotriene A4 methyl ester. C-alkylation of the tetrahy-dropyranyl ether of 3-butyn-l-ol with 2,2,3,3-tetradeuterio-l-iodopentane, prepared in 4 steps from propargyl alcohol, and subsequent protective group removal afforded the tetradeuteriated acetylenic alcohol 46 (equation 30). Semideuteriation of the alkynol and further transformation by known methods produced the labeled key reagent 3,4,6,6,7,7-hexadeuterio-(Z)-(3-nonen-l-yl)triphenylphosphonium iodide (47). Wittig olefination of epoxy dienal 45 with the labeled ylide generated from 47 completed the synthesis of... 

---