Studies on Silicon-Containing Fragrance Raw Materials( Ⅱ )——Syntheses and Odors of 4-Trimethylsilylcyclohex-3-enol and 4-Trimethylsilylcyclohexanol Derivatives

1-Substituted- 4-trimethylsilylcyclohex- 3-enol and 1-substituted- 4-trimetnylsilyl-cyclohexanol, 4-trimethylsilylcyclohex-3-enol and 4-trimethylsilylcyclohexanol, and some of their esters and carbon counterparts were synthesized. Structures of the nineteen new compounds were determined by 1H NMR, IR and MS. Their odors are evaluated.     

Gallium acylates and organogallium compounds

Conclusions The production of acylates of gallium and organogallium compounds of type Ar₂GaOOCR₂, ArGaOOCR₂ was described by a series of examples.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 564–566, March, 1968.     

Asymmetric oxidation of enol phosphates to α-hydroxy ketones by (salen)manganese(III) complex. Effects of the substitution pattern of enol phosphates on the stereochemistry of oxygen transfer

This paper presents a study of enantioselective catalytic oxidation of a variety of differently substituted, cyclic (E) and acyclic (Z)-enol phosphates. The asymmetric oxidation of acyclic (Z)-enol phosphates containing alkoxy substituents in the phosphate group 2a, c, e–g, i, and j and Z-configured enol phosphates containing aryloxy substituents in the phosphate group 2b, d, and h afforded optically active α-hydroxy ketones 4a–j of opposite configuration with good to high enantioselectivity. The influence of electronic and steric effects of the enol phosphate substituents on the stereoselectivity of oxidation was studied.     

Asymmetric epoxidation of (Z)-enol esters catalyzed by titanium(salalen) complex with aqueous hydrogen peroxide

Titanium(salalen) complex 1 was an effective catalyst for asymmetric epoxidation of enol esters. Although (E)-enol esters were reluctant to proceed, (Z)-enol esters underwent asymmetric epoxidation to give the epoxides in high yields with high enantioselectivity ranging from 86 to >99% ee in the presence of aqueous hydrogen peroxide as the stoichiometric oxidant. Complete enantioselectivity was observed in the reaction of (Z)-3,3-dimethylbut-1-en-1-yl 4-methoxybenzoate. The obtained epoxide was readily transformed into the corresponding 1,2-diol by reduction with lithium borohydride without erosion of the high enantiomeric excess.     

Synthesis of leaf aldehyde

The comparative oxidation of trans-hex-2-enol to leaf aldehyde has been effected with the aid of manganese dioxide, chromium oxide, and sodium dichromate in DMSO. It has been established that sodium dichromate in DMSO gives the best yield (not less than 80%) and a product of higher purity. It is a comparatively new reagent in organic synthesis. The use of sodium dichromate in DMSO is promising in the preparation of compounds requiring the use of mild conditions.Tartu State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 298–300, May–June, 1977.     

A study of the tautomerism of the N-butyl-4(2)-methoxycarbonyl-pyrrolid-3-ones and their hydrochlorides

The tautomerism of N-butyl-2-methoxycarbonyl-4-methylpyrrolid-3-one (I), N-butyl-4-methoxycarbonylpyrrolid-3-one (II), N-butyl-4-methoxycarbonyl-2-methylpyrrolid-3-one (III), N-butyl-4-methoxycarbonylpyrrolid-3-one hydrochloride (IV), and N-butyl-4-methoxy-carbonyl-2-methylpyrrolid-3-one hydrochloride (V) has been studied by UV and IR spectroscopy. It has been found that the esters I–V are highly ionized in aqueous and ethanolic solutions at concentrations of 10^–2–10^–3 M. On passing from methyl cyclopentran-1-one-2-carboxylate to the esters II and III the position of the equilibrium in heptane and CCl₄ shifts in the direction of the keto form. On passing from the esters II and III to the esters IV and V, the position of the equilibrium shifts in the direction of the enol. Meyer's relationship is not satisfied for the esters II and III, while it is satisfied for the esters IV and V. Hypotheses have been put forward on the causes of the phenomena mentioned.     

A mild and efficient synthesis of new pentafluorosulfanyl-substituted electron-deficient alkenes and allylsilanes

A series of pentafluorosulfanyl-substituted acrylic esters and amides have been synthesized in moderate to good yields from 3-pentafluorosulfanyl-prop-2-enol employing a chromic oxidation and subsequent coupling reaction. New pentafluorosulfanyl-substituted allylsilanes were also obtained from a SF₅-Cl addition on allylsilanes followed by a β-elimination reaction.     

1, 5-Rearrangement of enol acylates of aryl 1H.-1, 2, 4-triazol-1-ylmethyl ketones

The rearrangement of enol acylates of aryl 1H-1, 2, 4-triazol-1-ylmethyl ketones at 140–150°C in acetic anhydride is studied. The migration of the acyl group to the C(5) atom of the heterocycle is found to be intramolecular. The characteristics of the original and final products are presented. X-ray structural studies of the enol acetates of 2, 4-dichlorophenyl 1H-1, 2, 4-triazol-1-ylmethyl ketone and 2, 4-dichlorophenyl 5-acetyl-1H-1, 2, 4-triazol-1-ylmethyl ketone are carried out.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 560–564, March, 1993.     

Functionalized enamines—XXXII : Reaction of β-amino-α, β-unsaturated esters and amides with benzyl and cinnamyl bromides

Reactions of β-aminoacrylic esters (1–c) and amides (1d–o) with benzyl bromide 2 and cinnamyl bromide 3 give products which are dependent both upon the nature of the amine component of the enamine and, in the case of the amides, upon the amine from which the amide is derived. The β-enamino esters react with benzyl bromide to yield predominantly dialkylated products in the case of the pyrrolidine ester 1a. Reactions of the same esters with cinnamyl bromide yield mixtures of cinnamyl and 2-phenylpropenyl-substituted formylacetic esters. The enamino amides 1d–f react to yield the expected alkylated derivatives. The anilides 1i–o exhibit nucleophilic reactivity at the aniline nitrogen. A mechanism leading to the observed products is proposed.     

Ruthenium-catalyzed regio- and stereoselective addition of carboxylic acids to aryl and trifluoromethyl group substituted unsymmetrical internal alkynes

The regio- and stereoselective addition of carboxylic acids to aryl and trifluoromethyl group substituted unsymmetrical internal alkynes has been accomplished: the Ru(3)(CO)(12)/3PPh(3) catalyst system has effectively catalyzed the reaction to afford the trifluoromethyl group substituted (E)-enol esters with high regio- and stereoselectivities.