Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

3-Alkyl-l-alkynes

ALKYL-l-ALKYNES, 58, 1 ALKYL ARYL SULFIDES, 58,143 Alkyl aryl thioethers, 58,145 Alkylation, enolates, 56, 52 C-ALKYLATION, phase transfer catalysis... [Pg.111]

Alkyl-l-alkynes. Reaction of 1-bromo-l-alkynes (1) with at least 2 eq. of n-butyllithium in hexane gives 3-butyl-1-alkynes (2) in excellent yields. The favored mechanism involves metal-halogen exchange (a) and further reaction with n-butyllithium to give the dUithioalkyne (b), which is then alkylated at the propargylic carbon atom ... [Pg.85]

Alkylalkanoic acids, 388 Alkyl oj-alkenoates, 313 3-Alkyl-l-alkynes, 85 6-N-Alkylaminouracils, 185 Alkyl aryl ethers, 645 Alkyl aryl ketones, 24 N-Alkylarylsulfonamides, 578 o-Alkylbenzaldehydes, 443 Alkyl benzoates, 347 o-Alkylbenzoic acids, 368 2-Alkyl-l-f-butylaziridines, 118 Alkyl f-butylperoxyglyoxalates, 82 Alkyl chlorides, 22, 259 6-Alkyl-A -cyclohexenones, 236... [Pg.367]

The alkynylation of estrone methyl ether with the lithium, sodium and potassium derivatives of propargyl alcohol, 3-butyn-l-ol, and propargyl aldehyde diethyl acetal in pyridine and dioxane has been studied by Miller. Every combination of alkali metal and alkyne tried, but one, gives the 17a-alkylated products (65a), (65c) and (65d). The exception is alkynylation with the potassium derivative of propargyl aldehyde diethyl acetal in pyridine at room temperature, which produces a mixture of epimeric 17-(3, 3 -diethoxy-T-propynyl) derivatives. The rate of alkynylation of estrone methyl ether depends on the structure of the alkyne and proceeds in the order propar-gylaldehyde diethyl acetal > 3-butyn-l-ol > propargyl alcohol. The reactivity of the alkali metal salts is in the order potassium > sodium > lithium. [Pg.68]

The base-catalyzed fragmentation of 4-alkyl-l,2,3-thiadiazoles is a useful method for the preparation of alkyne-1-thiolates <1996T3171>. These alkyne-l-thiolates can then react with carbon disulfide to afford l,3-dithiole-2-thiones. This strategy has been developed to give a synthesis of some novel tetrathiafulvene derivatives <1996T3171>. [Pg.473]

A convenient approach to synthesize novel selenium-(3-lactams, namely 3-selena-l-dethiacephems 200, was accomplished via the regioselective iodocycli-zation reaction (Scheme 73) [103]. The key starting materials, alkyne-selenoureas 201, for this approach were readily prepared by the A-alkylation reaction of the corresponding previously known propargyl-azetidinones with a wide variety of isoselenocyanates under basic conditions. First, the reaction of (3-alkyne-selenourea... [Pg.44]

Alkylbromoborancs (1) can also be used to provide frans-alkenes by hydroboration of a 1-bromo- 1-alkyne. The adducts rearrange with sodium methoxide to (trans-l-alkyl-l-alkcnyl)boronate esters (3), which can be converted into either tran.v-alkenes (4)or ketones (5), as shown inequation III.7... [Pg.136]

Benzylmanganesepentacarbonyl, BzlMn(CO)s (1) indenols,1 Aryl ketones react with 1 selectively at the orr/io-position to form a manganacycle (2), which after oxidative decarbonylation with (CH3)3NO in CH3CN is converted into a product (a) that reacts regioselectively with alkynes to form substituted l-alkyl-l//-inden-7-ols (3). This reaction is regioselective a terminal alkyne reacts to form 2-sub-... [Pg.234]

Alkynes undergo reduction to produce c/ i-alkenes, which in turn undergo further reduction to the alkane. With alkyl-substituted alkynes, the reactivity of the triple bond is comparable with that of the double bond of the product alkenes, and extensive overreduction occurs. With 1-iodoalkynes, however, the reduced reactivity of the product m-l-iodoalkenes toward further reduction allows for the isolation of the t/i-l-iodoalkenes in good yields. An example is the reduction of the iodoalkyne (43) shown in equation (17).3 ... [Pg.477]


See other pages where 3-Alkyl-l-alkynes is mentioned: [Pg.784]    [Pg.345]    [Pg.784]    [Pg.345]    [Pg.497]    [Pg.2230]    [Pg.121]    [Pg.101]    [Pg.86]    [Pg.17]    [Pg.415]    [Pg.353]    [Pg.169]    [Pg.97]    [Pg.114]    [Pg.97]    [Pg.114]    [Pg.72]    [Pg.338]    [Pg.987]    [Pg.2404]    [Pg.45]    [Pg.45]    [Pg.217]    [Pg.294]    [Pg.72]    [Pg.86]    [Pg.329]    [Pg.561]    [Pg.987]    [Pg.387]    [Pg.97]    [Pg.114]    [Pg.582]    [Pg.401]    [Pg.387]   
See also in sourсe #XX -- [ Pg.85 ]




SEARCH



3 ALKYL 1 ALKYNES

Alkynes alkylated

Alkynes alkylation

L- alkyl

© 2024 chempedia.info