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A short and efficient asymmetric synthesis of the C12−C19 fragment of the cytotoxic macrolide (+)-peloruside A has been achieved via a highly diastereomer-discriminating RCM of α-branched but-3-enoate ester of a methallylic alcohol derived from hydrolytically resolved (S)-(−)-propylene oxide.

Two methods for the synthesis of C-methyldesoxy-sugars were proposed by desoxygenation of tertiary alcohol xanthogenates and hydrozirconation of exomethylene derivatives of carbohydrates.

A complete, stereocontrolled synthesis for erythronolide A was carried out by fusion of the (C9-C13)+(C7-C8)+(C1-C6) fragments from levoglucosan in 61 steps with 0.28% total yield.

A directed synthesis of a seco-acid derivative of 9(S)-dihydroerythronolide B has been carried out.

A synthesis of a C5-C9-fragment common to erythronolides A and B was carried out starting from levoglucosan.

A stereodirected synthesis of erythronolide B carbon chain was carried out starting from from levoglucosan.

A stereodirected synthesis of the C1-C6- and C1-C8-fragments of erythronolides A and B was carried out.

1.The general strategy for the synthesis of erythronolide B from levoglucosan was analyzed.2.The stereochemistry of the hydrogénation of the double bond in certain ?4,5-enopyranosides was investigated.3.The synthesis of methyl-2,4,7-tridesoxy-2,4-di-C-methyl-3-0-tert-butyldimethylsilyl-6-oxo-ß-L-idoheptopyranoside, the C1-C6 fragment of erythronolides A and B, was carried out.

The synthesis of 9-R-8-hydroxymethyl epi derivative of the seco acid 9-dihydroerythronolide B was carried out and its macrolactonization was studied.

The alkylation of indole and 2-methylindole with alkyl halides in the presence of a complex catalyst — dipyridinezinc chloride — was investigated. Nitromethane was used as the solvent. 3-Alkylindoles were obtained in 30–80% yields in all cases. The reaction mechanism is discussed. Data from the PMR and mass spectra are presented.

A stereodirected synthesis of erythronolide B from levoglucosane by coupling the C9-C13) + (C7-C8) + (C1-C6) fragments was carried out.

A synthesis of the C1-C10 fragment of erythronolides (A) and (B) with a reliably established configuration of the C3-C6 and C8 centers has been carried out.

1.Starting from levoglucosan, the C9-C13 fragment of 12-epineomethinolide has been synthesized in 15 steps (yield 4.5%).2.The C9-C13 fragment of methinolide has been synthesized by a new route in a yield of 29.4% based on l,2-O-isopropylidene-3-0-benzyl-5,6-di-O-acetyl-a-D-glucofuranose.

The C9-C13 fragment of neomethinolide has been synthesized from D-xylose.

1.Selenoesters react readily with a wide variety of organometallic reagents to give saturated ketones in high yields.2.Treatment of alkenyl copper (I) derivatives with selenoesters (or chloroanhydrides) in the presence of hexamethylphosphoramide gives excellent yields of a,ß-unsaturated ketones of varying structures.3.The syntheses of the components of the Peach moth pheromoneCarposia niponensis, namely, Z-12-nonadecen-9-one and Z-13-eicosen-10-one, have been described.

The rules governing the reaction of mixed carboxylic acid esters with dimethylaluminum methyl selenide have been investigated; it was found that the nature of the solvent and the structure of the precursor ester both exert significant effects on the selectivity of selenoester formation.

Conclusions A synthesis of three acyclic forms of the C9-C13 fragment of erythronolide B has been carried out.

Conclusions 1.An effective scheme of synthesis of 1,6-anhydro-2-desoxy-2-C-methyl-3-O-benzyl-4-methylene-ß-D-xylohexapyranose, an important intermediate compound in the synthesis of macrolide antibiotics, has been developed.2.A C9-C13 fragment of erythronolide A was synthesized in 14 stages from levoglucosan to give an overall yield of 7.5%.

Conclusions 1.A rearrangement was discovered of 1,6-anhydro-2-desoxy-2,4-di-C-methyl-3-O-benzyl-4-O-mesyl-ß-D-glactopyranose into 1,6-anhydro-2-desoxy-2,4-di-C-methyl-3-O-benzyl-5-O-mesyl-a-L-idofuranose.2.The C13-epi-C9-C13 fragment of erythronolide A was synthesized from levoglucosan in 18 stages in an overall yield of 3.4%.

The synthesis of the C9-C13 fragment of erythromycin A has been accomplished, starting from levoglusan (18 steps, 3.4%).

1.A general strategy for the synthesis of 14-membered macrolide antibiotics from suger derivatives is discussed.2.The synthesis has been carried out of the C1-C6 fragment common to the whole group of antibiotics, in 16 stages starting from levoglucosan, in an overall yield of 14%.

Using Cp2Zr(H)Cl, 1,6-anhydro-2-desoxy-2-C-methyl-3-O-benzyl-4-methylene-ß-D-xylohexapyranose has been reduced with a high degree of stereospecificity to 1,6-anhydro-2,4-didesoxy-2,4-di-C-methyl-3-Obenzyl-ß-D-galactopyranose, which was then converted into the C9-C13 fragments of erythronolide Band oleandonolide.

Conclusions An efficient method was proposed for the synthesis of 2,4-didesoxy-2,4-di-C-methyl-D-glucopyranose.

3-Indolylphenyliodonium trifluoroacetate reacts with ammonium bromide and lithium chloride and bromide to give 3-haloindoles. The reaction with ammonium chloride and tetrabutylammonium chloride leads to a mixture of 2- and 3-chloroindoles. The same mixture of chloroindoles is also formed by the action of lithium chloride but in the presence of 15-crown-5 ether. The course of the reaction is explained by ambident reaction of the cation of the iodonium salt.

3-Indolylphenyliodonium chloride and bromide, respectively, were obtained by the action of hydrochloric and hydrobromic acids on 3-indolylphenyliodonium betaine. Pyrolysis of the chloride leads to a mixture of 2- and 3-chloroindoles, while pyrolysis of the bromide leads only to 3-bromoindole. 1-Benzyl-2-chloroindole is obtained in the reaction of the betaine with benzyl chloride. The betaine reacts with dimethyl sulfate to give an iodonium salt, the reaction of which with lithium chloride and ammonium chloride leads to 1-methyl-2-chloroindole.

3-Indolylphenyliodonium tosylate and trifluoroacetate were synthesized, and their reaction with halide anions was investigated. It is shown that the iodonium grouping is replaced by halogen in all cases. 3-Fluoroindole was synthesized for the first time. The mechanism of the reaction is discussed, and data from the mass spectra of the 3-haloindoles obtained are presented.

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