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L- phenylethyl ester

Methyl-l-phenylethyl Ester (Cumyl Ester) RC02C(CH3)2C6H5 Cleavage... [Pg.245]

Methyl-l-phenylethyl (Cumyl) Ester RC02C(CH3)2C6H5 Formation... [Pg.402]

An efficient synthesis of optically active pentanedioates is possible using ester enolates based on chiral alcohols. This is illustrated by the addition of the lithium (fl-cnolate of (1 R,2S,5R)-5-methyl-2-(1-methyl-l-phenylethyl)cyclohexyl propanedioate to methyl ( )-2-butenoate at — 100 °C which shows simple and induced diastereoselectivity. [Pg.972]

The one-pot dynamic kinetic resolution (DKR) of ( )-l-phenylethanol lipase esterification in the presence of zeolite beta followed by saponification leads to (R)-l phenylethanol in 70 % isolated yield at a multi-gram scale. The DKR consists of two parallel reactions kinetic resolution by transesterification with an immobilized biocatalyst (lipase B from Candida antarctica) and in situ racemization over a zeolite beta (Si/Al = 150). With vinyl octanoate as the acyl donor, the desired ester of (R)-l-phenylethanol was obtained with a yield of 80 % and an ee of 98 %. The chiral secondary alcohol can be regenerated from the ester without loss of optical purity. The advantages of this method are that it uses a single liquid phase and both catalysts are solids which can be easily removed by filtration. This makes the method suitable for scale-up. The examples given here describe the multi-gram synthesis of (R)-l-phenylethyl octanoate and the hydrolysis of the ester to obtain pure (R)-l-phenylethanol. [Pg.133]

Acetic acid, chloro-, 5-methyl-2-(l-methyl-l-phenylethyl)cyclohexyl ester, [lR-(la,28,5a)]-, 65, 203... [Pg.231]

Methyl-2-(l-methyl-1-phenylethyl)cyclohexanone, (2S.5R)- Cyclohexanone, 5-methyl-2-(l-methyl-l-phenylethyl-, (2S-cis)- (65337-06-6), 65, 203 5-Methyl-2-(l-methyl-l-phenylethyl)cyclohexyl chloroacetate, (1R,2S,5R)- Acetic acid, chloro-, 5-methyl-2-(1-methyl-1-phenylethyl)cyclohexyl ester, [lR-(la,Z0,5a)]- (71804-27-8), 65, 203 5-Methyl-2-[l-methyl-l-(phenylmethylthio)ethyl]cyclohexanone, cis- and trans 65, 215... [Pg.253]

Treatment of ethyl l- 2-[(tm-butyl, dimethylsilyl)oxy]-l-phenylethyl -6-alkylpiperidine-2-carboxylates with 10% HF in MeCN afforded diastereo-meric mixtures of 4-phenyl-6-substituted perhydropyrido[2,l-c][l,4]oxazin-1-ones (94JOC3769). Dieckmann cyclization of ethyl 4-(3-ethoxy-carbonylpropyl)morpholine-3-carboxylate with ferf-BuOK in Et20 and subsequent ester hydrolysis and decarboxylation furnished perhydropy-rido[2,l-c][l,4]-oxazin-9-one (82EUP57536 92BMC1293). Mild acidic hydrolysis of the nitrile moiety of amino nitrile 185 gave pyrido[2,l-c][l,4]ox-azin-l-one 60 (96TL4001). [Pg.215]

Pereira [38] separated enantiomers of sec.-alcohols on Carbowax 20M after their conversion into carbamates by treatment with optically pure / -(+)-N-l -phenylethyl isocyanate. This reagent is prepared from commercially available R-(+)-1 -phenylethylamine and phosgene. 3(3-Acetoxy-As-etienic acid esters [39] were used for the same purpose. [Pg.90]

The different properties of ILs, with regard to their polarity, hydrophobicity, and solvent miscibility behavior through combination with different anions, are the reason for the different biocatalyst activities. Good to excellent activity of CALB was observed with a decrease in polarity and hydrophobicity and a viscosity increase of the ILs. In [bmim][PF6] a conversion of (R)-l-phenylethanol into the ester of 48.9% and an ee of 95.6% were achieved after 5h and 100% of (R)-l-phenylethanol was converted into the enantiopure (R)-l-phenylethyl acetate after a 1-day reaction. Immobilized CALB exhibited excellent stability, activity, and selectivity towards the (R)-enantiomer of 1-phenylethanol in [bmim][PF6]. In some research bis(trifluoromethylsulfonyl)imide-based ILs have been regarded as very suitable media for biocatalysis [39, 46, 50]. On the contrary, in the present work, lower suitability of the same IL was demonstrated. Since immobilized CALB catalyzed both hydrolytic and transesterification reactions, its enantioselectivity for long reaction times was lower. [Pg.117]

Intramolecular conjugate-type addition of the anions of A -[(5)-l-phenylethyl]amides 1 to a,/ -unsaturated esters results in the formation of cyclic acetic acid derivatives 231-33. [Pg.1103]

Peptide hydrazides are readily obtained by hydrazinolysis of suitably protected peptides linked to the resin via a benzyl ester.Alternative to the hydroxymethyl ester linkage of the Merrifield resins, l-methyl-2-oxo-phenylethyl ester,2-nitrobenzyl ester O or 4-meth-oxybenzyl ester type linkages are also utilized.b - Recently, fuUy protected hydrazides were obtained in good yields on 2-methoxy-4-alkoxybenzyl alcohol resin (Sasrin ) by hydrazinolysis with 20% anhydrous hydrazine in DMF using DMA as solvent the reaction was significantly slower, but with less side products. [Pg.431]

Caged compounds have the advantage of exhibiting their activities when and where we wish them to do so, in combination with microinjection. Allan et al. S3mthesized a potential photoactivatable caged ABA, the l-(2-nitro)phenylethyl ester (13), which was microinjected into guard cells [16]. ABA was released internally by UV photolysis and subsequently caused stomatal closure. This result suggests intracellular ABA perception. [Pg.332]

A 1-phenylethylamino moiety is used for diastereomeric control not only in addition of nucleophiles to A-(l-phenylethyl)imines but also in diasteroselective Michael addition to a,P-unsaturated esters. Thus, lithium A-(l-phenylethyl)-A-benzylamide 148 is employed for a one-pot tandem Michael addition-fluorination reaction (see Scheme 9.32) [58]. The reaction provides a/i/f-3-amino-2-fluoroesters 149 exclusively, whose diastereoselectivi-ties (64-66% de) to the chiral carbon of the 1-phenylethyl-group are good enough. [Pg.230]

Optically active phosphorus(iii) acid esters PhR P (OR ) have recently been prepared for the first time by the reaction of a chiral phosphorus chloride and an alcohol or thiol in the presence of an optically active amine, in this case (-)-NN-dimethyl-(l-phenylethyl)amine. (See also Refs. 449 and 450). A kinetic investigation shows that phosphorous acid and chloral react to give 2,2,2-trichloro-l-hydroxyethyl phosphonate at a much lower rate than the corresponding reaction with dimethyl hydrogen phosphite. Phosphorus trichloride and dialkyl phosphites (R0)2P(0)H have been shown to react at low temperature in the presence of pyridine, producing tris(dialkoxyphosphoryl)phosphines [(RO)2P(0)]3P. ... [Pg.310]

For the preparation of the 10-ethyl-10-deaza analogues rac,L-(IV.108), cf,L-(IV.108), and /,l-(IV.108), a somewhat different scheme was followed to form the required racemic or optically active acid ester (IV.114) [124], The dilithium salt of 4- -propylbenzoic acid was condensed with allyl bromide, and the resulting acid was esterified with MeOH-HCl to obtain the olefinic ester, (IV.115). On oxidation with Ru02-NaI04, (IV.115) yielded (IV.114) (77%). Resolution of (IV.l 14) was achieved efficiently with J-(l-phenylethyl)amine. The remaining steps from (IV.l 14) to (IV. 108) were the same as those used to form the 10-methyl-10-deaza analogue, (IV.107). [Pg.79]

Crot ox y phos 1 -[(Di m et hoxyphasp h i rtyI )oxy - 2-butenoic acid I-phenylethyl ester 3-hydroxycrotonic acid ester dimethyl phosphate 0,0-dimethyl 0-[l-methyl-2-( -phenytcarbethoxy)vinyl] phosphate dimethyl 2 methyl ben zyloxycarbonyl)-1-methyl vinyl... [Pg.407]


See other pages where L- phenylethyl ester is mentioned: [Pg.159]    [Pg.372]    [Pg.260]    [Pg.201]    [Pg.159]    [Pg.372]    [Pg.260]    [Pg.201]    [Pg.179]    [Pg.17]    [Pg.5]    [Pg.29]    [Pg.122]    [Pg.129]    [Pg.185]    [Pg.459]    [Pg.45]    [Pg.25]    [Pg.110]    [Pg.332]    [Pg.383]   
See also in sourсe #XX -- [ Pg.332 ]

See also in sourсe #XX -- [ Pg.27 , Pg.332 ]

See also in sourсe #XX -- [ Pg.332 ]




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2- -1 -phenylethyl

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