The pilot project MERCUR investigated the potentials of E-Learning in the crafts sector in Germany. The focus of research and development was on the design of a virtual academy for the crafts sector and an internet-based learning environment. This article exemplifies the experiences of learners and teachers. 1. DEVELOPMENT AND TESTING OF E-LEARNING IN THE CRAFTS TRADE In the passed years E-Lear...

A series of cyclic enediyne-containing amino acids with ring sizes varying from 10 to 12 atoms have been prepared starting from propargylglycine and homopropargylglycine. Their reactivity towards Bergman cyclisation under elevated temperatures has been explored. The enediynes displayed marked differences in cyclisation half-lives depending on the olefinic substituent and the ring size. A potent...

The stereochemical course of the cyclisation reaction catalysed by the bacterial 1,8-cineol synthase from Streptomyces clavuligerus was investigated using stereospecifically deuterated substrates. In contrast to the well investigated plant enzyme from Salvia officinalis, the reaction proceeds via (S)-linalyl diphosphate and the (S)-terpinyl cation, while the final cyclisation reaction is in bot...

Short liquid crystalline polymers in a nematic environment are very unlikely to cyclise. Hairpins, abrupt chain folds, favour cyclisation. As a result the cyclisation rate constant exhibits a maximum as a function of chain length. The maximum corresponds to a new object, a "ringlet". The rate constant also depends exponentially on temperature. This suggests excimer fluorescence as a probe of co...

In contrast to a biomimetic electrophilic cyclisation cascade, we employ a contra-biomimetic nucleophilic cyclisation cascade to give the tricyclic core of 4-hydroxy-GR24 in a single step. Kinetic resolution using a stereoselective Noyori transfer hydrogenation enables the concise synthesis of any enantiomerically enriched 4-hydroxy-GR24 stereoisomer.

Vinylogous esters bearing para or meta methoxy benzyl groups undergo oxidative cyclisation with 5-20 mol% iodobenzene and m-CPBA to give spirofuran or benzopyran containing heterocycles. The reaction allows rapid generation of skeletal complexity in good to excellent yields via a novel oxidative cyclisation.

A new method for preparing naphthyl amines from 1,5 unsaturated dicarbonyl precursors is described; the utility of this new method was proven in the syntheses of several natural products, all containing the benzo[c]phenanthridine core and enabled by a radical promoted cyclisation of the naphthyl amine products formed in the key cyclisation.

A series of new N4 and N8 macrocycles has been prepared, that includes cis-exogenous O2, S2 and S/O atoms to allow chelation to a metal external to the macrocyclic ring. We found that thioamide units within the macrocycles were unstable to attack by secondary amines and thus alkylated precursors containing only tertiary amines could lead to exogenous-S2 macrocycles. Cyclisation of alkylated tet...

S-(1-Oxido-2-pyridinyl)-1,1,3,3-tetramethylthiouronium hexafluorophosphate (HOTT) facilitates the first examples of efficient radical cyclisation with (hetero)aromatic substitution via Barton ester intermediates. Cyclopropyl and alkyl radicals allow access to five, six and seven-membered alicyclic-ring fused heterocycles with and without an additional fused cyclopropane, including the skeleton ...

Regioselective and stereospecific directed C–H arylation of simple amine substrates, cyclisation, delivered 30 diverse, three-dimensional scaffolds.