Tremblay et al., A Convenient Synthetic Method for Alpha-Alkylation of Steroidal 17-Ketone: Preparation of 16β-(THPO-Heptyl)-Estradiol, Synthetic Communications, vol./Iss: 25 (16), pp. 2483-2495, 1995.Tremblay R, Auger S, Poirier D. A convenient synthetic method for alpha-alkylation of ...
Scheme 1. Synthesis of derivatives A1–A5 through dienone phenol rearrangement of ring A. The structure of α,β-unsaturated ketone in ring A can be reduced by common reducing agents, such as Pd/C, LiAlH4, NaBH4, etc. Under the condition of 3.5 atm and Pd/C as the catalyst, α-s...
α,β-Unsaturated aldehydes protected as imines by reaction with primary amines undergo tandem vicinal dialkylation;163 when enantiomerically pure amino acid esters are used to generate these imines, the reaction sequence can proceed with good levels of asymmetric induction from the diastereodifferentiating...
Ketone Enolate ion attacks a C=O and the alkoxide is protonated. The net result is addition. Condensation with Esters Loss of alkoxide ion results in nucleophilic acyl substitution. KetoEnol Tautomers • Tautomers are isomers which differ in the placement of a hydrogen. • One may be ...
Allylic chlorides and acetates can oxidatively add to a coordinatively unsaturated palladium(0)–triphenylphosphine catalyst at temperatures as low as −78 °C. Syn–anti interconversion is not observed until the solution is warmed to −45 °C. Thus, alkylation of a syn-η3-allyl complex at...
A two-step sequence is described for conversion of cyclic and acyclic ketone enolates into α-methylenevalerolactones. The first step involves Michael addition to ethyl α-((phenylsulfony)methyl)acrylate 1 with concomitant elimination of PhSO 2 and formation of unsaturated keto esters 2-7. In th...
Alkylation Reactions to Introduce Substitutents R2 Scheme 1d illustrates the introduction of the alkyl substituents R2 by means of an alkylation reaction. In this procedure, the esters 1 are first reacted with a base such as sodium hydride or sodium hexamethyldisilazide, in an aprotic solvent ...
amination, N‐alkylation, N‐arylationketone derivatives (acyclic compoundscyclohexane derivativesketone derivatives (benzene compoundsTitanium pyrrolyl complexes are effective catalysts for the synthesis of α,β-unsaturated imines, which can be further functionalized using Rh-catalyzed alkene or alkyne ...
1.An odoriferous or aroma substance comprising an aldehyde, substituted in alpha position by an alkyl residue, of the formulahaving(I) a total of 13 C atoms, whereinR means an unbranched alkyl residue having 6, 7, 8 or 9 C atoms andR′ means an unbranched alkyl residue having 2, 3, ...
The alkylation of the amino group shown in Step 2 i) (reaction b) may be carried out using any of the procedures known in the art for the N-alkylation of amines and which will not racemize the chiral centre. Suitable alkylating agents may be selected from compounds of formula R56L in ...