Phenyl 2-propenyl ether

Phenyl 3-phenyl-2-propenyl ethers 448, which feature a latent oxonium ion functionality, cyclize upon treatment with acid to afford the chroman 449 as a mixture of diastereomers. Reduction of the chroman 449 with Raney nickel affords a single diastereomeric product 450 (Scheme 102) <2005TL3719>. 

We recently reported a convenient and efficient synthetic route to new 3-substituted 2,3-dihydrobenzo[h]furans 278 based on the tandem cyclization-y-alkylation of 2-bromophenyl ( )-3-phenyl-2-propenyl ether 276 whose operational simplicity could find favor in many applications161. Previous attempts using 2-bromophenyl (E)-2-propenyl ether failed because the cyclic intermediate underwent a y -elimination. We thought that a likely strategy to overcome the y-elimination in the cyclic (2,3-dihydrobenzo[h]furanyl)methyllithium intermediate could be substitution by a phenyl moiety that could provide increased resonance stabilization to the cyclic lithium intermediate 277 (Scheme 85). 

Figure 5. Correlation of rate of hydration of terminal alkenes with

Phenyl 2-propenyl ether (AUyl phenyl ether)... 

Mallavadhatni, U.V. and Rao, Y.R. (1994) Enantioselective synthesis of dnnamyl-l-phenyl-2-propenyl ether a metabolite of marine green algal spedes Caulerpa racemosa. Tetrahedron Asymmetry, 5, 23-26. 

Addition of a lithium amide to the propenyl ether 318 gave 319 in 38-73 % yield" (equation 75). A phenyl group in 318 was necessary to produce the aminocyclopropanes (319) presumably by its stabilizing effect on the intermediate carbanion. 

The cyclization of the nitrogen analog of 1-phenyl-2,2.2-trichloroethyl 2-propenyl ether shows very similar stereoselectivity, the cf. -2.4-disubstituted pyrrolidine derivatives are selectively formedl5. In each example only one diastereomer is observed. 

Furthermore, compound 3, 4-phenoxy-2-(trifluoromethyl)phenyl 3,3-dichloro-2-propenyl ether, showed unique lethal symptoms as well as insecticidal activity against S. litura at 500 ppm, motivating us to use this 3 as the next lead compound (Fig. 30.3.2) [4, 5]. 

Nishina and Yamamoto have also reported the gold(I)allenes with alcohols [109]. As an example, treatment of a neat mixture of p-tolyl allene and isopropanol with a catalytic 1 1 mixture of (PPh3)AuCl and AgOTf at 30 °C led to isolation of isopropyl )-3-(4-tolyl)-2-propenyl ether in 98% yield (Eq. (12.39)). The protocol was most effective for monosubstituted and 1,3-disubstituted allenes and gave no transfer of chirality for the hydroalkoxylation of 1-phenyl-l,2-butadiene. Horino has reported the gold(I)-catalyzed intermolecular addition of alcohols to the allenyl moiety of 4-vinylidene-2-oxazolidinones [110]. 

To a suspension of 2.24 g (20 mmol) of potassium rerf-butoxide in 20 mL of terf-butyl methyl ether under argon is added 2.31 g (10 mmol) of (S)-2-(methoxymethyl)-1-[( )-3-phenyl-2-propenyl]pyrrolidine30, and then the mixture is cooled lo — 78 °C and 7.1 mL of 1.69 M fm-butyllithium in pentane is added dropwise with stirring. After 2 h, 12 mmol of the haloalkane are added and the mixture is stirred until the brown-red solution becomes yellow. Then 30 mL of diethyl ether and 20 mL of 2 N hydrochloric acid are added, the mixture stirred for 12 h at 25 °C, extracted with three 40-mL portions of CH2CI2, the organic layer is washed with two 10-mL portions of NaHCOj and two 10-mL portions of water, dried with Na2S04, concentrated in vacuo and distilled (Kugelrohr). 

Azadienes of this sort were studied simultaneously by Mariano et al., who reacted mixtures of (1 ,3 ) and (1E, 3Z)-l-phenyl-2-aza-l,3-pentadiene 275 with several electron-rich alkenes, e.g., enamines and enol ethers (85JOC5678) (Scheme 61). They found the (l ,3 )-stereoisomer to be reactive in this process affording stereoselectively endo 276 or exo 277 piperidine cycloadducts in 5-39% yield, after reductive work-up with sodium borohydride. The stereochemistry of the resulting adducts is in agreement with an endo transition state in the case of dienophiles lacking a cis alkyl substituent at the /8-carbon (n-butyl vinyl ether, benzyl vinyl ether, and 1-morpholino cyclopentene), whereas an exo transition state was involved when dihydropyrane or c/s-propenyl benzyl ether were used. Finally, the authors reported that cyclohexene and dimethyl acetylenedi-carboxylate failed to react with these unactivated 2-azadienes. 

Substituted allyl aryl ethers undergo a Claisen rearrangement similar to the reaction described in text Section 24.13 for allyl phenyl ether. 2-Butenyl phenyl ether rearranges on heating to give o-( 1-methyl-2-propenyl)phenol. 

ClOH120 2-methyl-2-propenyl phenyl ether 5820-22-4 448.65 38 973 1.2 19611 C10H12O2 2-(p-tolyl)propionic acid 938-94-3 504.61 44.327 2... 

A phenol group may reacts with double bonds to give phenyl substituted cyclic enol ethers. Thus, treatment of 2-(l-oxo-3-phenyl-2-propenyl) phenol (15) (2-hydroxychal-cones) with PdCl2 causes intramolecular attack of the hydroxy group at the olefinic double bond to form flavone (16)10 A different type of oxidation of phenols with PdCl2... 

Operation of the insertion-elimination mechanism has been demonstrated in the reaction of rhodium hydride complex, RhHL4 (L=PPh3), with two isomeric allyl phenyl carbonates [56]. Unbranched 2-butenyl phenyl carbonate was found to give branched allylic phenyl ether exclusively, whereas the decarboxylation of the branched l-methyl-2-propenyl phenyl carbonate afforded unbranched 2-butenyl phenyl ether. These results can be accounted for by assuming a precata-lytic and catalytic insertion-elimination process as shown in Scheme 7. 

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