29643-79-6

Upstream product

• 19041-17-9 methyl 4-bromo-3-methylbut-2-enoate 
• 100-52-7 benzaldehyde 
• 541-47-9 3-Methylbutenoic acid 
• 10295-26-8 acide γ-bromosenecioique 
• 87121-05-9 bis(trimethylsilyl) vinyl ketene acetal 
• 109751-82-8 (E)-4-trimethylsilyl 3-methyl 2-butenoate de trimethylsilyle 
• 60335-71-9 4-Methyl-2-phenyl-3,6-dihydro-2H-pyran 
• 28010-27-7 2-((E)-1-Methyl-3-phenyl-allylidene)-malonic acid 
• 340167-06-8 4-methyl-2-oxo-6-phenyl-5,6-dihydro-2H-pyran-3-carboxylic acid 
• 594822-07-8 [3-methyl-1-(prop-2-enyloxy)but-3-enyl]benzene 
• 727425-78-7 β,γ-dibromo-isovaleronitrile 
• 850856-96-1 β,γ-dibromo-isovaleric acid methyl ester 
• 25436-25-3 trimethylsilyl 3,3-dimethylacrylate 
• 62477-64-9 4-[(trimethylsilyl)methyl]but-3-enoic acid 

Downstream Products

• 134962-95-1 4-methyl-6-phenyl-5,6-dihydro-2H-pyran-2-ol 
• 20430-09-5 (2Z,4E)-3-methyl-5-phenylpenta-2,4-dienoic acid 
• 197522-46-6 (Z)-3-methyl-5-phenyl-2-pentene-1,5-diol 
• 60335-71-9 4-Methyl-2-phenyl-3,6-dihydro-2H-pyran 

Relevant academic research and scientific papers

Three-step assembly of 4-aminotetrahydropyran-2-ones from isoxazoline-2-oxides

Tetrahydropyran-2-ones with a 4-amino function connected to a tertiary carbon atom-a widely naturally occurring fragment-are constructed by a three step protocol from easily available isoxazoline 2-oxides. In the first stage, the carbon skeleton of the target product is formed upon a C,C-coupling of a silyl ketene acetal with a nitronate function, under silyl triflate catalysis. The key step of the assembly consists of the oxidative cleavage of an endocyclic N-O bond of intermediate cyclic nitroso acetals with mCPBA, accompanied with lactone ring closure, and gives rise to β-nitro-δ-lactones in 63-85% yields. The latter are reduced with amalgamated aluminium, to furnish the target scaffold.

[3 + n] Annulation reactions by means of 3-trimethylstannyl-2-[(trimethylstannyl)methyl]propene, an isobutene dianion synthetic equivalent

Stepwise functionalization of the two carbon-tin bonds in 3-trimethylstannyl)-2[(trimethylstannyl)methyl]propene with electrophiles (diacyl dichlorides or aldehydes and carbon dioxide, provides a promising route for [3 + n] annulation reactions.

SUR LA REACTION DE REFORMATSKY. II-PREPARATION ET REACTIVITE DE L'ORGANOZINCIQUE ISSUS DU SEL BROMOZINCIQUE DE L'ACIDE γ-BROMOSENECIOIQUE.

The condensation of benzaldehyde and cyclohexanone with the bromozinc salt derived from γ-bromosenecioic acid, in the presence of zinc, yield unsaturated hydroxyacids or lactones.The equilibration of the intermediary alcoxides is studied.

A survey of mono- or bis-decarboxylation of β-methyl polyethylenic-malonic acids

Diverse experimental conditions, leading to mono- or bis-decarboxylation of β-methyl polyethylenic-malonic acids, were examined. A clean and easy bis-decarboxylation was reported.

Synthesis of conjugated γ- and δ-lactones from aldehydes and ketones via a vinylation(allylation)-ring closing metathesis-oxidation sequence

Nucleophilic C-vinylation and C-allylation of aldehydes and ketones followed by O-allylation of the obtained carbinols gave the corresponding allyl or homoallyl ethers, respectively. Ring-closing metathesis of these compounds afforded in many cases cyclic ethers (dihydrofurans and dihydropyrans, respectively) bearing disubstituted and trisubstituted C=C bonds. These were then subjected to allylic oxidation to yield conjugated γ- and δ-lactones. Reasons for the observed failures are presented and discussed.

Biocatalyzed preparation of the optically enriched stereoisomers of 4-methyl-2-phenyl-tetrahydro-2H-pyran (Doremox)

The four stereoisomers of the rose oxide analogue Doremox were prepared in enantiomerically enriched form by enantiospecific bakers' yeast reduction of suitable derivatives and by lipase-mediated kinetic resolution of diol precursors.

A general synthesis of (2Z)-terpenoic acids

A three-step synthesis of (2Z), (4E)-polyenic acids 6 is described. Condensation of aldehydes 1 with potassium prenal enolate led to dihydropyranols 3 which were oxidized into dihydropyrones 5, precursors of (2Z), (4E)-polyenic acids 6. The procedure was applied to a synthesis of 13- cis-retinoic acids from β-ionylidene acetaldehydes. (C) 2000 Elsevier Science Ltd.

Synthesis of conjugated γ- and δ-lactones from aldehydes and ketones via a vinylation/allylation-ring closing metathesis-oxidation sequence

Nucleophilic C-vinylation or C-allylation of aldehydes and ketones followed by O-allylation of the obtained carbinols gave the corresponding allyl ethers. Ring-closing metathesis of the latter afforded cyclic ethers (dihydrofurans and dihydropyrans, respectively) which were then subjected to allylic oxidation to yield conjugated γ- and δ-lactones.

A New Synthesis of 5-Substiuted 3-Methyl-2-phenylthio-2-penten-5-olides

Dienolate 11, which was produced from 3-methyl-2-phenylthio-2-butanoic acid (1), and two equivalents of LDA, reacted with aldehydes or ketones to give 5-alkyl-3-methyl-2-phenylthio-2-penten-5-olides (12) in good yields.

3-Methyl 1,1-bis(trimethylsiloxy) 1,3-butadiene et 4-trimethylsilyl 3-methyl 2-butenoate de trimethylsilyle: preparations et reactions avec le benzaldehyde

The regioselectivity of the reaction between benzaldehyde and the silylketene acetal prepared from trimethylsilylsenecioate is studied as a function of the catalyst used.CsF leads exclusively to the "branched" product whereas TiCl4 gives the required "lin