A novel polyfunctional chiral building block derived from (S)-ethyl lactate. Application to the synthesis of the sex pheromone of the southern corn rootworm (Diabrotica undecimpunctata howardi)

Highly enantiomerically pure (4S, 5E)-4-bromomethylhept-5-enenitrile was prepared from (S)-ethyl lactate by a six-step procedure involving a rearrangement of chiral cyclopropylcarbinol. This product was used for the synthesis of the sex pheromone of the southern corn rootworm (Diabrotica undecimpunctata howardi), (10R)-10-methyltridecan-2-one. For preliminary communication, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 151–155, January, 2000.     

New synthesis of serricornin,the sex pheromone of the cigarette beetle (Lasioderma serricorne)

A new approach to the total synthesis of serricornin, the sex pheromone of the cigarette beetle, based on readily available (4S,5E)-4-methyhept-5-enenitrile was implemented.     

(R)-4-Menthenone in the synthesis of optically pure sex pheromone of the peach leafminer moth (Lyonetia clerkella)

The synthesis of (14S)-methyloctadec-1-ene, sex pheromone of the peach leafminer moth (Lyonetia clerkella), is described to demonstrate a new potential of the synthetic use of (R)-4-menthenone.     

Enantiospecific synthesis of (S)-(+)-3-methylheneicosan-2-one, an analog of the sex pheromone of the German cockroach (Blatella germanica L.) from (−)-(1R,4S)-menthone

An enantiospecific synthesis of (S)-(+)-3-methylheneicosan-2-one, an analog of the sex pheromone of the German cockroach (Blatella germanica L.), was carried out through selective transformations of (3R,6S)-3,7-dimethyloctane-6-olide obtained from (−)-menthonevia the Baeyer—Villiger reaction. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1071–1073, May, 1997.     

Thermodynamic properties of chiral liquid crystalline material (S)-4-(2-methylbutyl)-4′-cyanobiphenyl (5*CB)

As a part of a project of clarifying the physical properties and dynamics of cyanobiphenyls with chiral molecules, thermodynamic properties of (S)-4-(2-methylbutyl)-4′-cyanobiphenyl (5*CB) were investigated by adiabatic calorimetry between T = (5 and 350) K. The complicated phase behaviour was solved and the thermodynamic functions were determined. A new glass transition was identified in the phase II (metastable crystal) at T = 105 K. No inversion of the stability between two crystalline phases was found, being contrary to the expectations from the previous neutron scattering studies.     

Novel synthesis of (4<Emphasis Type="Italic">R</Emphasis>)-4-methylpentanolide from (L)-(−)-menthol

A novel synthesis of the promising optically pure chiral (4R)-4-methylpentanolide that is based on several regiospecific oxidative transformations of (4R)-2,4-dimethyl-1-(1-methylethyl)-1-cyclohexene, the product of addition of (–)-menthone and methylmagnesium iodide followed by acid dehydration, was proposed.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 451–453, November–December, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis of isomeric 2-oxazolidinones from (1<Emphasis Type="Italic">R</Emphasis>,2<Emphasis Type="Italic">R</Emphasis>)-and (1<Emphasis Type="Italic">S</Emphasis>,2<Emphasis Type="Italic">S</Emphasis>)-2-amino-1-(4-nitrophenyl)-1,3-propanediols

A synthesis is reported for (4R,5R)-and (4S,5S)-4-hydroxymethyl-5-(4-nitrophenyl)oxazolidin-2-ones and (1′R,4R)-and (1′S,4S)-4-[hydroxy(4-nitrophenyl)methyl]oxazolidin-2-ones from (1R,2R)-and (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediols. The effect of the experimental conditions on the formation of these compounds was studied. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1562–1570, October, 2007.     

Synthesis of (S)-6-methylhept-5-en-2-ol, the aggregation pheromone ofGnathotrichus sulcatus

An enantioselective (ee−50%) four-step synthesis of (S)-6-methylhept-5-en-2-ol (“sulcatol”), which is the aggregation pheromone ofGnathotrichus sulcatus, from 3S,7-dimethylocta-1,6-diene was developed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 713–717, April, 2000.     

Optically pure acyclic bifunctional compounds from (−)-menthone. Synthesis ofR-4-methyl-1-nonanol,the sex pheromone of the larger flour beetle (Tenebrio molitor L.)

A number of novel methyl-branched chirones were prepared starting from (–)-menthone and making use of a novel, efficient, and selective oxidant, decanepersulfonic acid (DPSA). Optically pure (4R)-methyl-1-nonanol, the sex pheromone of the larger flour beetle (Tenebrio molitor L.), was synthesized.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1301–1303, July, 1993.     

Stereoselective total synthesis of the (Z)-isomer of a novel phytotoxic nonenolide from Phomopsis sp. HCCB03520 and its C-6 epimer

The (Z)-isomer of a phytotoxic nonenolide, (6S,7R,9R)-6,7-dihydroxy-9-propylnon-4-eno-9-lactone isolated from Phomopsis sp. HCCB03520 and its C-6 epimer have been synthesized through a common route starting from butyraldehyde. The synthesis involves enantioselective Maruoka allylation, Sharpless asymmetric epoxidation and intramolecular ring closing metathesis as the important steps.     

New chiral spiro[2.5]octanones as products of methylenation of (3<Emphasis Type="Italic">R</Emphasis>, 6<Emphasis Type="Italic">R</Emphasis>)-2-arylidene-6-isopropyl-3-methylcyclohexanones with dimethylsulfoxonium methylide. Synthesis,stereochemistry, and behavior in liquid-crystalline systems

Methylenation of (3R,6R)-2-(4-X-benzylidene)-6-isopropyl-3-methylcyclohexanones (X = F, Cl, Ph) with dimethylsulfoxonium methylide occurs stereoselectively to give 1(S)-(4-X-phenyl)-5(R)-isopropyl-8(R)-methyl-3(R)-spiro[2.5]octanones, whose stereochemistry was established by ¹H NMR spectroscopy. The configuration of the chiral centers in the cyclohexanone fragment and its preferred conformation (methyl is axial and isopropyl is equatorial) in the products do not change with respect to the starting enones. The mutual trans-arrangement of the carbonyl and aryl groups at the newly formed three-membered ring was established; the aryl group also occupies the trans-position with respect to the axial methyl group of the cyclohexanone fragment. Using methylenation of the compound with X = Ph as an example, a mixture of by-products resulting from oxidative hydroxylation at the α-position relative to the carbonyl group was isolated. The resulting chiral spiro[2.5]octanones induce a helical supramolecular ordering in the nematic mesophase of 4-pentyl-4′-cyanobiphenyl and exhibit a twisting power only somewhat (by 20–30%) lower than the starting enones. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2331–2341, October, 2005.