Acetylenic carbonyl compounds

Addition of vinylic organometallic compounds to unsaturated carbonyl compounds addition of organometallic compounds to acetylenic carbonyl compounds... 

Camphor- 10-sulfonic acid, 62 Unsaturated acetals or ketals Nickel boride, 197 (2R,4R)-Pentanediol, 237 Acetylenic carbonyl compounds a,p-Unsaturated acetylenic carbonyl compounds... 

Acetylenic carbonyl compounds Di-/x-carbonylhexacarbonyldicobalt, 99 Tributyltin chloride, 315 Acyl halides Acyl fluorides... 

Tris(dimethylamino)sulfonium difluo-rotrimethylsilicate, 336 Xenon(II) fluoride, 345 Alkyl bromides Potassium permanganate, 258 Sodium bromide, 46 Tetraethylammonium bromide, 46 Alkyl iodides Aluminum iodide, 17 Potassium permanganate, 258 Sodium iodide, 46 Tetraethylammonium iodide, 46 Alkynes (see also Acetylenic carbonyl compounds, Diynes, Enynes, Propar-gyl alcohols)... 

Propargyl alcohols By addition of alkyl groups to acetylenic carbonyl compounds (R)-( + )-/-Butyl p-tolylsulfinylacetate, 59... 

Unsaturated carbonyl compounds (see also Acetylenic carbonyl compounds, Allenic carbonyl compounds) Unsaturated acids a,P-Unsaturated acids Sodium chlorite, 280 7,8-Unsaturated acids L-Valinol, 341... 

Addition of NaX or BuJNX to l-alkyn-3-ones.1 In the presence of these two reagents, sodium or ammonium salts undergo conjugate addition to acetylenic carbonyl compounds. This reaction provides mm-P-halovinyl ketones or N,N-diethyl m-P-haloacrylamides. 

Upon heating to 300-350 °C the ethynyl vinyl oxiranes 36, obtained by condensation of vinylsulfonium ylides with acetylenic carbonyl compounds, underwent a Cope-transposition into the oxacycloheptadiene 37, followed by a Claisen-type reaction leading to a cis, trans mixture of 2-ethynylcyclopropanecarboxaldehydes 38, Eq. (12)25). 

Organocopper-organoborane complexes (RCu BR3) have been recently discovered to add to a,p-acetylenic carbonyl compounds with a high stereospecificity at low temperatures (—70 to —20 °C), which cannot be achieved with reagents previously available (Eq. 91)... 

Addition to ot, -acetylenic esters and ketones (3, 108 6, 163-164). The addition of organocopper reagents to conjugated acetylenic carbonyl compounds is usually not stereospeciflc, although cis-addition predominates. Japanese chemists have found that the stereoselectivity in the reaction with alkylcopper reagents is markedly enhanced by use of the complex RCu BRj. Thus the reaction of dimethyl acetylenedicarboxylate with n-butylcopper complexed with tri-n-butylboron (or triethylboron) results in exclusive formation of the cis-adduct. In the absence of a trialkylborane the cis- and adducts are formed in the-ratio 85 15. 

Acetylenic carbonyl compounds in synthesis of heterocycles using reactions with dinucleophilic reagents 87KGS291. 

Schreiber, J., et al. Synthesis of acetylenic carbonyl compounds by fragmentation of a,P-epoxy ketones with p-tolylsulfonylhydrazine. Helv. Chim. Acta 1967, 50, 2101-2108. 

The immediate product (246) of 1,3-dipolar cycloaddition of a 16-diazoandrostan-17-one (245) on to an acetylenic carbonyl compound rearranged spontaneously to give a pyrazole derivative (247). ... 

Stereospecific synthesis of 1,3-dienes. Corey et a .3 have described a new synthesis of 1,3-dienes based on the highly stereospecific cis addition of alkylcopper reagents to a, -acetylenic carbonyl compounds (3, 108). Thus the reaction of methyl 4-trimethyl-siloxy-2-nonynoate (l)4 in THF with divinylcopperlithium (1.25 eq) at —90° and then at — 78° affords the pure e(r adduct (2) in > 90% yield. Treatment of (2) with methanolic hydrochloric acid effects cleavage of the trimethylsilyl ether and lactonization to give (3). 

Hydroboration, the addition of borane (or diborane) to n-donor substrates such as alkenes, acetylenes, carbonyl compounds, and so on, is a most useful synthetic reaction and was developed by the extensive work of Brown et al. 2 "52 In the absence of more nucleophiUc n- and n-donor sites, borane will also attack a bonds in alkanes, silanes, and aromatic compounds to yield addition, cleavage, and rearrangement products. The interaction of borane with hydrocarbons involves 3c-2e bonded pentacoordinate carbons. 

Conjugate addition is also a feature of the reaction of organocuprates with a,p-acetylenic carbonyl compounds. By conducting the reaction at —78 °C, high yields of cis addition compounds can be obtained (1.163). This allows the stereocontrolled... 

Natural rubber (hevea) is 98% c/ -l,4-polyisoprene with 2% 3,4-structure. It can be synthesized by anionic polymerization with alkyllithium compounds or with Ziegler-Natta catalysts [220-225]. The polymerization is carried out in solvents. Impurities such as acetylenes, carbonyl compounds, hydrogen sulfide, and water have to be removed [217,226-228]. 

Cyclocondensation of 5-aminopentadienones of type 153, formed by addition of 3-aminocrotonates to acetylenic carbonyl compounds or condensation with (S-diketones, affords derivatives of nicotinic acid 154 (Bohlmann-Rahtz synthesis) ... 

---