Mercuration-reductive demercuration of glycals: A mild and convenient entry to 2-deoxy-sugars

Bettelli, Enzo; Cherubini, P.; D’Andrea, Piero; Passacantilli, Pietro; Piancatelli, Giovanni

doi:10.1016/s0040-4020(98)00281-6

Cited by 41 publications

(21 citation statements)

References 17 publications

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“…Hydroxymercuration/demercuration of intermediate 1 under standard conditions (Bettelli et al, 1998) resulted in the formation of all four possible diastereomers of the desired acetal (intermediates 2). Fortuitously, this mixture of diastereomers could be partially resolved using standard silica gel chromatography (DCM as mobile phase) to give two pairs of two diastereomers (Fig.…”

Section: Methodsmentioning

confidence: 99%

Stereoselective Chemical Defense in the Drosophila Parasitoid Leptopilina heterotoma is Mediated by (−)-Iridomyrmecin and (+)-Isoiridomyrmecin

et al. 2012

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Chemical defense mechanisms are widespread among insects but have rarely been demonstrated in parasitoid wasps. Here, we show that the Drosophila parasitoid Leptopilina heterotoma (Hymenoptera, Figitidae) produces (−)-iridomyrmecin and (+)-isoiridomyrmecin in a cephalic gland, and that these chemicals have a highly repellent effect on ants. Stereoselective synthesis of 4 stereoisomers of iridomyrmecin allowed us to demonstrate that the repellent effect of iridomyrmecins depends on the stereochemistry. Potential food items impregnated with natural doses of (−)-iridomyrmecin were avoided by ants much longer than those impregnated with (+)-iridomyrmecin, (+)-isoiridomyrmecin, or (−)-isoiridomyrmecin, respectively. Quantitative headspace analyses revealed furthermore that females and males of L. heterotoma released iridomyrmecins in higher amounts when confronted with ants. This is the first time, that (−)-iridomyrmecin and (+)-isoiridomyrmecin are reported as natural products. Females synthesize more iridomyrmecins than males, and the most active (−)-iridomyrmecin is produced by females only. We, therefore, hypothesize that this defense mechanism is used mainly by female wasps when foraging for Drosophila larvae on rotten fruits, but also may protect male wasps during dispersal.

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Section: Methodsmentioning

confidence: 99%

Stereoselective Chemical Defense in the Drosophila Parasitoid Leptopilina heterotoma is Mediated by (−)-Iridomyrmecin and (+)-Isoiridomyrmecin

et al. 2012

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“…[24] To our surprise, the subsequent hydrolysis of 16 with mercury acetate under previously reported reaction conditions [25] provided an unexpected elimination product (α,β-unsaturated aldehyde). By using a modified procedure, [26] we were pleased to find that treatment of the methyl enol ether 16 with mercury acetate at 0°C in THF/H 2 O (v/v, 4:1) followed by the addition of 8 % KI solution gave aldehyde 17 in 75 % yield. Takai ole-Scheme 3.…”

Section: Introductionmentioning

confidence: 99%

Total Syntheses of Cochliomycin B and Zeaenol

Gao

Wang

et al. 2014

Eur J Org Chem

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Divergent syntheses of two 14‐membered resorcylic acid lactones (RALs), cochliomycin B (6) and zeaenol (22), have been accomplished. The key feature in our strategy was the facile construction of three contiguous stereogenic centers in the title molecules by using natural L‐arabinose as the chiral template. The key reactions included Takai olefination, Suzuki cross coupling, transesterification, and a late‐stage ring‐closing metathesis (RCM).

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“…10 The primary alcohol was selectively mono protected as tosylate 11 16 and treated with NaBH 4 to result in a terminal methyl compound 17. 12 The primary hydroxyl group was converted to iodide 11 upon treatment with I 2 , triphenyl phosphine, and imidazole (Scheme 2).…”

Section: Introductionmentioning

confidence: 99%