Applications of Organotin Derivatives for Carbohydrate Synthesis

Department of Chemistry, Dalhousie University, Halifax Canada B3H4J3 

Two types of tin derivatives have been used mainly to achieve these reactions dialkylstannylene acetals are formed by reaction of dialkyltin oxides with diols tributyltin ethers are formed by reaction of bis(tributyltin) oxide with alcohols. Some aspects of the regioselectivity achieved with these two types of intermediates are the same, while others are different, as will be outlined in the sections to follow. Where the reaction outcomes are similar, the dialkyltin reagents are strongly preferred because of their lower toxicity. As these reagents are heavily employed, the topic has been reviewed several times, but siguilicant uew observatious continue to be made. This chapter is not intended to be a comprehensive summary of all applicatious of these intermediates, but will highlight examples of each type of selectivity. 

Tin Chemistry Fundamentals, Frontiers, and Applications Edited by Marcel Gielen, Alwyn Davies, Keith Pannell and Edward Tiekink 2008 John Wiley Sons, Ltd. ISBN 978-0-470-51771-0 

Nomenclature of Organic Compounds (see Table 5.1.4) 2,2-dialkyl-l,3,2-dioxastannolanes if the ring is live-membered 2,2-dialkyl-l,3,2-dioxastanninanes if the ring is six-membered or 2,2-dialkyl-1,3,2-dioxestannepanes if the ring is seven-membered. Trialkyltin ethers are also termed trialkyltin alkoxides or trialkylstannyl ethers. 

The use of pre-formed dibutyltin dimethoxide is advantageous, if considerably more expensive reaction of diols are complete in 5 to 15 minutes in benzene at reflux. This technique avoids the problems with working in methanol mentioned above and gives better yields. Stannylene acetals have also been prepared in situ using sub-stoichiometric dibutyltin dichloride. The preparation of stannylene acetals is also accelerated by microwave irradiation and selective reactions can be performed in low yields on some diols and polyols by microwave irradiation in the presence of a catalytic amount of dibutyltin oxide. Microwave irradiation in the presence of stoichiometric dibutyltin oxide gives excellent yields of stannylene acetals in 5 min at 150 °C. ° 

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