A. V. Buevich

SYNTHESIS AND STRUCTURE OF TRICYCLIC FURANOSESQUITERPENOIDS RELATED TO PALLESCENSIN A

Electrophilic cyclization of (cyclo)farnesanes containing anexo-methylene group in the a-isoprenoid unit smoothly gives regio- and stereoisomeric octalins subsequently transformed to tricyclic furanosesquiterpenoids related to metabolites of some marine organisms.

NEW APPROACH TO THE SYNTHESIS OF LACTONES OF THE IRIDANE SERIES

A new approach to the synthesis of lactones of the iridane series starting from (±)-linalool was developed. Synthesis of a bicyclic iridoid structurally related to the naturally occurring iridolactone villosol was performed.

Study of the rearrangement of cyclononatetraenyl(dipropyl)borane to 7,8-dipropyl-7-borabicyclo[4.2.2]deca-2,4,9-triene by NMR spectroscopy

Using NMR spectroscopy it was found that at ambient temperature 9-cyclononatetraenyl(dipropyl)borane (1) rapidly rearranges to give 7,8-dipropyl-7-borabicyclo[4.2.2]deca-2,4,9-triene (2),cis-endo-9-dipropylborylbicyclo[6.1.0]nona-2,4,6-triene (3a), and two isomeric boranes with dihydroindene skeletons (4a,b) (the ratio2 :3a :4a,b is 10 : 1 : 2).cis-exo-9-Dipropylborylbicyclo[6.1.01nona-2,4,6-triene (3b) is an intermediate product of the rearrangement; it is formed as a result of 8π-electrocyclization inE,Z,Z,Z-cyclononatetraenyl(dipropyl)boranela. The transformation of bicycle3b to final product 2 occurs apparently via a synchronous exchange of the groups at the B atom (the transformation of the cyclopropane ring to the boracyclobutane ring accompanied by simultaneous migration of the propyl group from the B atom to thea-C atom). Borane6 formed in this rearrangement rapidly isomerizes to2via a [1,3]-B shift.

Z-Stereoselective Peterson olefination of ketones

A highly-stereoselective method (90 % of theZ-isomer) was developed for the Peterson olefination of ketones with nerylacetone (1) as an example. The method is based on the introduction of a PhS group, which is removed after completion of the reaction, at the ketone C(3) atom.

Unusual transformation of trimethylsilyloxyisoxazolidines initiated by the fluoride ion

It was found that opening of the isoxazolidine ring of 6aα-isopropenyl-1α/β-trimethylsilyloxy-3, 3aα,4,5,6,6a-hexahydro-(1H)-cyclopent[c]isoxazoles by the F− ion initially gives an intermediate, a tertiary nitrosocompound detected by UV and NMR spectroscopy. Its transformation, finally, into α,β-unsaturated aldoximes probably involves an unprecedented allylic migration of the nitroso group.

Synthesis of (Z)-trisubstituted olefins with all substituents different from methylvia α,β-disubstituted (E)-acroleins

Abstract(E)-2,3-Disubstituted allyl bromides readily accessible in two steps from the corresponding enals react with dialkyl cuprates in a high regio- and stereoseiective fashion to give (Z)-trisubstituted olefins with all substituents different from methyl. This reaction was used in the synthesis of benzyl 7-methyl-3-propyldeca-(2Z,6Z)-dienyl ether, a derivative of a component of the sex pheromone of the lesser apple wormLaspeyresia pomonella L.

Cationic cyclization of (α-furyl)- and (β-furyl)methyl derivatives of (±)-limonene

Cationic cyclization of the α- and β-furylmethyl (±)-limonene derivatives to give tricyclic furanoterpenoids, related to the metabolites of some marine organisms, was studied.

Chemistry of natural compounds and bioorganic chemistry Synthesis of (±)-furodizinin and (±)-furodizin

The racemic forms of natural Omnoterpenoids, (±)-furodizinin and (±)-furodizin, were synthesized by cationic cyclization of the α or β-furylmethyl derivatives of linalool, geraniol and nerol.

Synthesis ofZ-11-octadecenal, the sex pheromone of the wax moth

A new synthesis ofZ-11-octadecenal, the sex pheromone of the wax mothAchroia grisella starting from methyl 10-undecenoate is elaborated.

Synthesis of 1,4-dimethylhydroazulene derivatives fromtrans-3-isopropenyl-2-(2-methoxycarbonylethyl)cyclopentanone

The title cyclopentane keto ester was used as the key compound in stereoselective syntheses of 1,4-dimethylhydroazulene derivatives which served as precursors for guaiane type sesquiterpenes.