Vinyl carbinol

The rearrangement in Entry 9 occurs spontaneously on warming of the reaction mixture from addition of an organolithium reagent to form the vinyl carbinol unit. This is a very general means of constructing reactants for oxy-Cope rearrangements that leads... 

Three divinyl carbinol substrates have been chosen as examples. They are good substrates for examination because the vinyl carbinols are known to undergo Sharpless reaction at low reaction rates. The results presented in Table 4-7 clearly show that the ee of 79 improves as the reaction proceeds toward completion. Note that the minor enantiomer 78 can be removed through a second, faster epoxidation that converts enantiomer 78 into an easily destroyed bis-epoxide 80 (Scheme 4-29 and Table 4-7). The same trend is apparent in the second demonstration with diisopropenyl carbinol 81 (Scheme 4-30 and Table 4-8). Similarly, the third reaction is the reaction of (E,E)-divinyl carbinol 82 (Scheme 4-31 and Table 4-9). 

Synonyms AA AI3-14312 Allyl al Allylic alcohol BRN 0605307 Caswell No. 026 CCRIS 747 EINECS 203-470-7 EPA pesticide chemical code 068401 3-Hydroxypropene 3-Hydroxy-propylene NSC 6526 Orvinyl carbinol Propenol Propenol-3 Propen-l-ol-3 l-Propenol-3 1-Propen-3-ol 2-Propenol 2-Propen-l-ol Propenyl alcohol 2-Propenyl alcohol RCRA waste number P005 UN 1098 Vinyl carbinol Weed drench. 

Methods for oxidative transformations continue to receive attention. Nickel peroxide on graphite oxidizes geraniol to citral in 89% yield. Three groups report " the oxidative rearrangement of tertiary vinyl carbinols. Linalool is con-... 

Butenes were subjected to photosensitized reaction with molecular oxygen in methanol. 1-Butene proved unreactive. A single hydroperoxide, l-butene-3-hydroperoxide, was produced from 2-butene and isolated by preparative gas chromatography, Thermal and catalyzed decomposition of pure hydroperoxide in benzene and other solvents did not result in formation of any acetaldehyde or propionaldehyde. The absence of these aldehydes suggests that they arise by an addition mechanism in the autoxidation of butenes where they are important products. l-Butene-3-hydroperoxide in the absence of catalyst is converted predominantly to methyl vinyl ketone and a smaller quantity of methyl vinyl carbinol —volatile products usually not detected in important quantities in the autoxidation of butene. 

A sample of the methanolic oxidation product was treated directly with powdered sodium borohydride. Water was added, the solvent allowed to evaporate, and the aqueous solution extracted with carbon tetrachloride. Methyl vinyl carbinol was shown to be the major product, but about 10% impurities were present. Reduction by stirring overnight with 1.0 Af sodium sulfite followed by extraction with carbon tetrachloride produced a solution which analyzed as methyl vinyl carbinol with about 1% impurities. 

Decomposition of a 0.07M solution of 2-butene-3-hydroperoxide in benzene at 100°C. had a half-life of 23 hours. The final products were 37% methyl vinyl ketone, 37% methyl vinyl carbinol, and 26% acetone. Attempts to substantiate the identity of the acetone were unsuccessful, but it was the only anticipated product with the correct gas chromatographic retention time on four different absorbents. 

The cleanest product composition may be effected by decomposition of the pure hydroperoxide or solutions in the injection block of the gas chromatograph. In carbon tetrachloride solution only methyl vinyl ketone and methyl vinyl carbinol were produced, the ratio of ketone to alcohol being 2.9. No definite traces of products from isomerized hydroperoxide were observed. 

Such a rearrangement was detected only in the presence of sulfuric acid, and furthermore at 100°C. it was supplanted by a homolytic breakdown. The products found in the purely thermal decomposition—methyl vinyl ketone and methyl vinyl carbinol—are in fact consistent with the behavior of alkyl hydroperoxides and are analogous to the products produced from the cyclic allylic hydroperoxide from cyclohexene (2). 

Of the many studies of the autoxidation of butenes, few (5,11) have emphasized methyl vinyl ketone and methyl vinyl carbinol as major products. In the cumene hydroperoxide-initiated oxidation of 1-butene at 105°C. with 60 atm. of air, Chernyak (5) reported an average hourly rate of production of these two products approximately equal to the combined rates of formation of hydroperoxide and epoxide. The reported rates for hydroperoxide plus vinyl ketone and alcohol indicate that 60% of the products occur by abstraction, in agreement with Van Sickle (17). 

ALLYL ALCOHOL Vinyl Carbinol, 2-Propen-l-ol Flammable Liquid, I 3 3 0 ... 

Vinyl Carbinol. See in Vol 1, A135-R to A136-L under Allyl Alcohol.. 

For conversion of ketones into a,/3-unsaturated aldehydes containing two additional carbon atoms, several multistep processes via ethynyl or vinyl carbinol intermediates have been reported.4-10 Although the overall yields obtained by these routes for the conversion of cyclohexanone into cyclohexylideneacetaldehyde have never exceeded 50%, they were the only useful methods for this type of conversion until the excellent process of Wittig11 appeared. This process consists of normal aldol condensations of ketones with the lithium salt of ethylidenecyclohexylamine and subsequent dehydration and hydrolysis. 

Vinylaniline. See Aminostyrene A257-L Vinyl Carbinol. See Allyl Alcohol A135-R... 

Allyl Alcohol (Vinyl Carbinol, Propenyl Alcohol, 2-Propeno-1, Propenol-3)... 

The first step is an allylic chloride displacement on a chlorosulfite ester generated from the tertiary vinyl carbinol and thionyl chloride. Attack of chloride on an allylic carbocation intermediate can equally well be envisaged. The subsequent conversion is simply an S 2 displacement by acetate ion (Scheme 10.6). 

FEMA No. 2805 Amyl Vinyl Carbinol CH3(CH2)4CHCH=CH2 mushroom, herbaceous oils ins—water/ mL 95% ale... 

Synonyms and trade names vinyl carbinol, propenyl alcohol, 2-propeno-l, propenol-3... 

The D-seco-acid (326) has been prepared by Diels-Alder reaction between the trimethoxy-vinyl-carbinol (325) and methyl acrylate, followed by reduction with sodium in liquid ammonia. ... 

Ring expansions of appropriately a-substituted ketones via their vinyl carbinol derivatives has also been carried out under cationic conditions. The basic sequence, outlined in Scheme 66, begins with the addition of a vinyl organometallic to an a-substituted ketone, where X is carbon or a heteroatom. Departure of a leaving group Y then produces a cationic species, which may react further to form products. Two main pathways appear to be operative one is a cationic alkene cyclization, followed by a pinacol-like rearrangement while the other is a 3,3 or 3,3-like rearrangement, followed by an intramolecular alkylation of the intermediate enol. 

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