The advantages of stable glycosyl donors for saccharide coupling are many, and we describe herein the utility of propargyl glycosides for anomeric activation and glycoside synthesis exploiting the alkynophilicity of AuCl3. Various aglycones were reacted with propargyl glycosides, resulting in the formation of an alpha,beta-mixture of glycosides and disaccharides in good yields.

We acknowledge that Drs. Zoe Pikramenou and Peter Glover (University of Birmingham) first prepared and provided a sample of the nonfluorinated Er(tpip) 3 compound for initial studies, though none of the work detailed in this paper has utilized that sample. Table 1 should read as follows: a Obtained with graphite-monochromated Mo KR (λ ) 0.71073 Å) radiation for 1, 3, 4, and 5, and synchrotron radiation (λ ) 0.775 Å) for 2 and 6. Supporting Information Available: An incorrect spatial correction file was used for the X-ray detector at the Advanced Light Source of Lawrence Berkeley National Laboratory. This caused systematic errors in the lattice parameters and peak prediction and resulted in poor integration and loss of highangle data for compounds 2 and 6. A reintegration of the X-ray diffraction data for these compounds using the correct spatial correction file provided a more precise refinement of the crystal structures. Updated CIF files have therefore been submitted for compounds 2 and 6. This material is available free of charge via the Internet at http://pubs.acs.org. We have now found that the transglycosylation reaction we described does not proceed in the presence of organic bases such as triethyl amine and diisopropylethyl amine. Furthermore, propargyl glycosides do not behave as glycosyl donors in dioxane‚HCl or Et 2 O‚HCl. Interestingly, the transglycosylation reaction between the propargyl per-O-benzylated glucoside (4a) and menthol (6a) proceeded with 5 mol % of HAuCl 4 in acetonitrile at 60°C, giving 45% of lactol 5a and 30% of menthyl glucoside 5b.The authors thank the reader who suggested these experiments.

Diversity oriented synthesis of tricyclic compounds was achieved using a combination of the Ferrier reaction and the Pauson-Khand reaction. Ferrier reaction was effected using NbCl5, and the Pauson-Khand reaction was carried out using Co2(CO)8, acetonitrile-dimethoxyethane. Michael additions using various alkyl, aryl, and heterocyclic thiols were also performed successfully. The Ferrier, Pauson-Khand, and Michael addition reactions were found to be highly diastereoselective.

Allen (I) reagiert bei 130°C zu einem Gemisch der Dimeren (II)‐(VII) neben Pentameren.