I. P. Tsypysheva

Stereochemical Aspects of the Beckman Rearrangement of Oximes of Levoglucosenone and Its Dihydro Derivative. Enantioselective Synthesis of (+)-γ-Pelargonolactone

Regiospecific C55 -halogenation with retention of configuration occurred upon Beckman fragmentation of levoglucosenone oxime using SOCl2 or PBr3. On the other hand, the oxime of its dihydro derivative gave under these conditions the C6 - substitution product. A stereoselective synthetic scheme for (+)-γ-pelargonolactone, an attractant for the rice and corn weevils Sitophiltus zeamais, was developed from the fragmentation product of levoglucosenone oxime.

Stereochemical differentiation in the reactions of organometallic reagents with levoglucosenone and some of its dihydro derivatives

The reactions of methylmanganese iodide with levoglucosenone, its dihydro derivative, and 1.6-anhydro-3-deoxy-4-O-methyl-β-d-erythro-hexopyran-2-ulose were found to be highly diastereoselective compared to the reactions of Li-, Mg-, and Cu-based reagents. This specific feature of the manganese reagent is due to the enhanced tendency of manganese for chelation.

APPROACHES TO FORMATION OF THE ELEUTHESIDE NUCLEUS BASED ON (+)- δ-CADINOL

1) Institute of Organic Chemistry, Ufa Scientific Center, Russian Academy of Sciences, 450054, Ufa, pr. Oktyabrya, 71, fax: (3472) 35 60 66, e-mail: chemorg@anrb.ru; 2) N. N. Vorozhtsov Novosibirsk Ins titute of Organic Chemistry, Siberian Division, Russian Academy of Sciences, 630090, N ovosibirsk, pr. Lavrent 1eva, 9, fax: (3832) 34 47 52, e-mail: gtolstik@nioch.nsc.ru. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 417-418, September-October, 2001. Original article submitted August 1, 2001.

Synthesis of 2-amino derivatives of levoglucosenone

Abstract2-Amino derivatives of levoglucosenone were prepared by reaction of the 2-methanesulfonyl (or p-toluenesulfonyl) derivatives with ammonia, methylamine, or octylamine under various conditions. The analogous reaction did not occur for saturated derivative 15. The 2-amino-3,4-dihydro derivative was prepared by catalytic hydrogenation of unsaturated amine 9.

Synthesis of the Eleutheside Core from (+)- Δ-Cadinol: Construction of Side Chains on the Menthane Ring

Methods for allylic oxygenation of (+)-δ-cadinol by SeO2 have been developed to study approaches to the formation of the eleutheside core from it. Diasteromeric alcohols and the product of their 1,4-oxacyclization, which is transformed into a bicyclic derivative containing the required functional groups to study the final cyclization into the eleutheside core, were prepared. The α-hydroxy derivative was converted after benzylation and ozonolysis into a mixed acetal, a convenient compound for performing the synthesis via an alternate route.

Functionalization of the Allyl Fragment in (+)-δ-Cadinol

Epoxidation, bromination, and iodination of the double bond in (+)-δ-cadinol under various conditions are accompanied by formation of 1,4- or 1,5-epoxy derivatives. By contrast, vicinal hydroxylation gives rise to “normal” products. Intramolecular cyclization of the resulting vicinal diols was studied.

Synthesis and molecular structure of methyl (3aS,4R,7aR,8aS,8bR,8cS)-8,8-dimethyl-1,3,7-trioxo-2-phenyl-2,3,3a,4,7,7a,8,8a,8b,8c-decahydro-1H-cyclopropa [4, 5]pyrano[3,2-e]isoindol-4-carboxylate

Heterocyclic compounds prepared from the monoterpene (+)-3-carene are used as intermediates in the synthesis of low-molecular-weight bioregulators and chiral ligands in asymmetric metal-complex catalysis [1]. Dienoate 1 [2] underwent a Diels–Alder reaction with N-phenylmaleinimide in order to synthesis new heterocyclic compounds containing a chiral monoterpene moiety. The structure of the single reaction product 2 was established using PMR and 13C NMR spectroscopy and 2D methods (COSY, HSQC, NOESY) and was confirmed by an x-ray structure analysis (XSA).

2,4 -Diazapenta -1,4 -dienes in the synthesis of 2,6 -diaryl -3,5 -dinitropiperidines

Abstract2,4,6-Triphenyl-and 2,6-diaryl-3,5-dinitropiperidines were synthesized in 70–79% yields by reaction of 1,3,5-triaryl-2,4-diazapenta-1,4-dienes with 2,2-dimethyl-and 2-phenyl-1,3-dinitropropanes.