VINYLOXY-ALKOXIDES

NEW DIASTEREOSELECTIVE C-C-COUPLING REACTIONS OF CARBOHYDRATE VINYL ETHERS WITH CARBONYL COMPOUNDS

Dörthe Vortmeyer

Organisch-Chemisches Institut, Westfalische Wilhelms - Universität, Corrensstraße 40, 48149 Münster, Germany

Vinyloxy-ethanol   1   and   derivatives   are   qualified   reagents   for   carbon-carbon-coupling reactions^[1,2,3]. The reaction occurs via formation of the intermediate 2 followed by attack of the carbonyl component 3 to get the β-hydroxy-1,3-dioxolanes 4.

To apply this new type of aldol reaction in carbohydrate chemistry the vinyl ethers 5 and 6 and the (E7Z)-1-propenyl ethers 7, 8, 9 and 10 are synthesized ^[4]. Each of them bearing a free hydroxyl group in a-position to the ether moiety.

In the following step the vinyl ethers are treated with a metall reagent and a carbonyl compound to give C-C-coupling products like 11. The reaction allows to control up to three new chiral centers in only one step with good to excellent diastereoselectivity ^[4].

References

[1] M. Schmeichel, H. Redlich, Synthesis 1996, 1002.

[2] P. Maier, H. Redlich, Synlett 2000, 257.

[3] P. Maier, Ph. D. Thesis, Universita't Munster 2003.

[4] D. Vortmeyer, Ph. D. Thesis, Universitat Munster 2004.