An easy and rapid method for the analysis of intact, non-desulfated glucosinolates by capillary zone electrophoresis (CZE) coupled to electrospray ionization-time of flight-mass spectrometry (ESI-TOF-MS) is described. Surprisingly, an electrolyte and a sheath liquid based on formic acid provided the best results. In this strongly acidic system, the glucosinolates were separated and detected as anions, resulting in an excellent selectivity. Thus, crude plant extracts could be analyzed without any interference of matrix constituents. The sensitivity together with mass accuracy and true isotopic pattern of the TOF-MS allowed identification of a broad series of glucosinolates in Arabidopsis thaliana seeds.

A new synthesis of bromo-and iodomethyl-substituted tetrahydrofurans has been devised. The sequence starts with the conversion of aryl-functionalized bis(homoallylic) alcohols 1 into N-alkenoxythiazole-2(3H)-thiones 6 or pyridine-2(1H)-thiones 7. When photolyzed in the presence of appropriate trapping reagents, thiones 6 and 7 efficiently liberated substituted 4-penten-1-oxyl radicals 2, which underwent synthetically useful 5-exo-trig cyclizations. Cyclized radicals 3 were trapped with BrCCl 3 or an adequate iodine atom donor (either n-C 4 F 9 I or diethyl 2-iodo-2-methyl malonate) to provide halocyclization products 4 or 5. This strategy has been applied for the synthesis of 3-, 4-, or 5-phenyl-substituted 2-(1-bromo-1-methylethyl)tetrahydrofurans 4a−c (75−90%, 36−96% de), which were not attainable as major products

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The analysis by HPLC, CE and CE-MS/MS of root bark extracts of a, so far undescribed, Central-African Ancistrocladus species (family Ancistrocladaceae) is described. Owing to the complexity of the extract, the application of reversed-phase HPLC resulted in a partially incomplete separation of the naphthylisoquinoline alkaloids, whilst CE using a non-aqueous buffer proved to be a very valuable complementary method for a first characterisation of the crude extract. By performing additional CE-MS/MS experiments, in combination with parallel isolation studies and structural elucidation using conventional methods, six alkaloidal substances present in the plant could be identified.

Short enantioselective syntheses of naturally occurring muscarine alkaloids 1a-d starting from (Z)-1,4-hexadiene (2) and its E-configured isomer 4 have been devised. Key transformations in both sequences were (i) asymmetric dihydroxylation of 1,4-hexadienes 2 and 4 and (ii) application of a novel diastereoselective bromoetherification of (2S,3R)-5-hexene-2,3-diol (3) (40% ee) and (2S,3S)-5-hexene-2,3-diol (5) (90% ee) which was initiated by a vanadium(V)-catalyzed oxidation of bromide using tert-butyl hydroperoxide as primary oxidant.Muscarine alkaloids 1 (Figure 1) 1 have been isolated from fungi of the genera Amanita, 2-4 Clitocybe, 5 and Inocybe. 6 The discovery that (+)-muscarine (1a) reliably reproduces some of the responses to a stimulation of the parasympathetic nervous system is generally regarded as a foundation stone of modern pharmacology. 7,8 Since a supply of pure alkaloids 1 from natural sources generally is associated with tedious purification steps using considerable amounts of fungi, 2,9 the synthesis of (+)-muscarine (1a), 10 (-)-allo-muscarine (1b), 11 (+)-epi-muscarine (1c), 12 (+)-epiallo-muscarine (1d), 13 and derivatives thereof 14 has received considerable attention in the last decades. Two principle strategies for this purpose have emerged: (i) stereoselective modification of substituted pento-or hexofuranoses 15 and (ii) diastereoselective ring closure reactions of ex-chiral pool-derived substrates. 16 In spite of the significant progress in stereoselective synthesis, to date the shortest route to alkaloids 1 from readily available starting materials still requires at least five steps. 15b In view of the significance of muscarine 1a and its derivatives we have devised a three-step sequence of all possible (2S)-configured muscarine alkaloids 1 starting from 1,4-hexadiene and disclose our results in this communication.Both isomers of 1,4-hexadiene 17 were selected as starting material for the synthesis of muscarine alkaloids 1. The enantioselective osmium-catalyzed dihydroxylation 18 was applied for constructing stereocenters at C2 and C3 in one step. Asymmetric dihydroxylation (AD) of (Z)-1,4-hexadiene (2) with AD-mix-b ® in the presence of H 3 CSO 2 NH 2 at 0 °C occurred selectively across the disubstituted double bond to furnish (2S,3R)-configured hexenediol 3 19,20 in 52% yield (40% ee, Scheme 1). Further, 8% of (Z)-4-hexene-1,2-diol (not shown in Scheme 1) were obtained. This product was separated by column chromatography 20 but no efforts were made to determine the absolute configuration of the major isomer since it was not associated with the synthesis of alkaloids 1. The observation that the enantioselectivity for formation of diol 3 is comparatively low reflects the well known reluctance of the 1,4-bis(9-Odihydroquinidyl)phthalazine auxiliary to provide substantial enantioselectivities in AD reactions of (Z)-configured olefins. 18 Therefore, the AD of (Z)-1,4-hexadiene (2) was repeated at 0 °C in the presence (9-O-indolylcarbamoyl)dihydroquinidine as chiral ligand. The latter r...