69573-50-8

Upstream product

• 23708-48-7 pentamethylenebis(magnesium bromide) 
• 116668-56-5 (S)-(+)-3-phenyldihydrofuran-2,5-dione 
• 464201-50-1 (S)-3-[(1Z,4R)-3-(1-hydroxycyclohexyl)-3-phenylprop-1-enyl]-4-(1-methylethyl)-5,5-diphenyloxazolidin-2-one 
• 14371-10-9 (E)-3-phenylpropenal 
• 136290-37-4 1-((E)-1-Ethoxy-3-phenyl-allyl)-1H-[1,2,4]triazole 
• 84017-22-1 (E)-3-cyclohexyl-3-phenylacrylic acid 
• 108-94-1 cyclohexanone 
• 940-43-2 N-methyl-3-phenylpropanamide 
• 464201-36-3 (S)-4-(1-methylethyl)-5,5-diphenyl-3-[(E)-3-phenylprop-2-enyl]oxazolidin-2-one 
• 4392-24-9 Cinnamyl bromide 
• 464201-56-7 (R)-2-methoxy-4-phenyl-1-oxaspiro[4.5]decane 

Relevant academic research and scientific papers

Metallations and reactions with electrophiles of 4-isopropyl-5,5-diphenyloxazolidin-2-one (DIOZ) with N-allyl and N-propargyl substituents: Chiral homoenolate reagents

N-Allyl, N-cinnamyl, and N-(3-trimethylsilyl)propargyl derivatives of 4-isopropyl-5,5-diphenyloxazolidin-2-one (DIOZ) are prepared by lithiation of the parent DIOZ (with BuLi in THF) and reaction with the corresponding bromides (Scheme 1). Lithiation in the same solvent, with deprotonation by BuLi on the allylic or propargylic CH2 group at dry-ice temperature, provides colorful solutions, which are either combined with aldehydes or ketones directly or after addition (with or without warming) of (Me2N)3TiCl or (i-PrO)3TiCl. Conditions have thus been elaborated under which all three types of conjugated lithium compounds react in the γ-position with respect to the oxazolidinone N-atom: carbamoyl derivatives of enamines and allenyl amines are formed in yields ranging from 60 to 80% and with diastereoselectivities up to 98% (Schemes 2-5). The C= C bond of the N-hydroxyalkenyl groups has (Z)-configuration (products 5 and 8), the allene chirality axis has (M)-configuration (products 9), and the addition to aldehydes and unsymmetrical ketones has taken place preferentially from the Si face. A mechanistic model is proposed that is compatible with the stereochemical outcome (assuming kinetic control and disregarding the presence of Li and Ti species in the reaction mixture; cf. L, M in Fig. 4). Hydrolysis of the enamine derivatives leads to lactols, oxidizable to γ-lactones, with recovery of the crystalline oxazolidinone, as demonstrated in three cases (Scheme 6). Thus, the application of chiral oxazolidinone auxiliaries (cf. Figs. 1 and 2) has been extended to the overall enantioselective preparation of homoaldols.

Benzotriazole- and 1,2,4-triazole-stabilized allylic anions: Applications in syntheses of functionalized α,β-unsaturated ketones, γ-lactones, γ-lactams, and β-substituted esters

Deprotonated 1-(benzotriazol-1-yl)-1-ethoxy-2-hexene (7) reacted with alkyl halides, aldehydes, ketones, imines, and α,β-unsaturated esters to give exclusively the α-alkylated products 8a-c, 10a,b, 12, 14, 16, and 18a,b, respectively. Without isolation, these products were hydrolyzed under mild conditions to generate the corresponding simple or functionalized α,β-unsaturated ketenes 9a-c, 11a,b, 13, 15, 17, and 19a,b. Similar reactions with the phenyl-substituted analog 3-(benzotriazol-1-yl)-3-ethoxy-1-phenyl-1-propene (21) also gave the analogous α-products, but they were accompanied by small amounts of the γ-products in most cases. By contrast, deprotonation of the corresponding triazole derivative 29 with butyllithium followed by reactions with alkyl halides, aldehydes, ketones, or imines yielded exclusively γ-alkylated adducts 32, 34, 36, 38, 40, and 42. Intermediates 32, 34, 36, 38, 40, and 42 were readily converted into β-substituted esters 33a-c, γ-lactones 35a,b, 39, 41, and 43, and γ-lactams 37a-c on hydrolysis.

Synthetic applications of the β-lithiation of β-Aryl secondary amides: Diastereoselective and enantioselective substitutions

The sequence of β-lithiation and electrophilic substitution of β-aryl secondary amides is reported. The lithiations occur regioselectively at the β-position, and the resulting lithiated intermediates can be reacted with a wide range of electrophiles to give substituted products. Reactions of β-lithiated amides bearing an α-substituent provide substituted products with high diastereoselectivity. Electrophilic substitutions of β-lithiated N-methylamides in the presence of the chiral diamine (-)-sparteine provide highly enantioenriched products. The methodology is used to synthesize enantioenriched β-aryl β-substituted amides, acids, and lactones.

Silyl Phosphites. XVIII. Versatile Utility of α-(Trimethylsilyloxy)-alkylphosphonates as Key Intermediates for Transformation of Aldehydes into Several Carbonyl Derivatives

Carbonyl addition compounds of diethyl trimethylsilyl phosphite (DTMSP) with aldehydes were converted, by treatment with lithium diisopropylamide (LDA) followed by the successive alkylation and alkaline hydrolysis, to carbonyl derivatives involving aldehydes, unsymmetrical ketones, β,γ-unsaturated ketones, and carboxylic acids. β-Substituted carboxylic esters and γ-substituted lactones were prepared by use of the carbonyl addition compounds of DTMSP with α,β-unsaturated aldehydes.

Synthesis of γ-Lactones and 3-Alkylidene-1-indanones

γ-Lactones are formed in high yields in the reactions of (E)-3-alkyl-3-phenylpropenoic acids in concentrated sulfuric acid if the alkyl groups contain a tertiary γ-hydrogen.If the alkyl groups bear secondary γ-hydrogens 3-alkylidene-1-indanones are formed almost exclusively.Reaction mechanisms for the cyclizations are discussed on the basis of deuteration experiments.

REACTION OF DI(BROMOMAGNESIO)ALKANES WITH UNSYMMETRICALLY SUBSTITUTED CYCLIC ANHYDRIDES

Alkylated γ-spirolactones were prepared in one-step reactions in high yields from butane-1,4-diyl and pentane-1,5 diyldimagnesium dibromides and substituted cyclic anhydrides in tetrahydrofuran.In the light of experimental findings electronic and steric factors influence the regiospecificity of this reaction.