948056-06-2Relevant articles and documents
Carbohydrate carbocyclization by a zinc-mediated tandem reaction and ring-closing enyne metathesis
Poulsen, Carina Storm,Madsen, Robert
, p. 4441 - 4449 (2002)
Methyl 5-deoxy-5-iodo-pentofuranosides are reductively ring-opened and propargylated in a tandem fashion in the presence of zinc. The 1,7-enynes thus obtained are subjected to ring-closing enyne metathesis with catalyst B to produce functionalized 1-vinyl cyclohexenes. By adding BnNH2 to the tandem reaction, an amino group can be introduced in the 1,7-enyne products. Addition of 2-TMS-ethynylcerium(III) chloride after the reductive ring-opening produces the corresponding 1,6-enynes. Further annulation of the product 1,3-dienes can be achieved through a Diels - Alder reaction with good control of stereochemistry. These procedures constitute efficient methods for rapid carbocyclization and annulation of carbohydrates to produce a variety of functionalized five- and six-membered ring systems.
A concise synthetic route to the conduritols from pentoses
Keinicke, Lise,Madsen, Robert
, p. 4124 - 4128 (2007/10/03)
A short synthetic strategy for preparation of the conduritols is described. The key step employs a zinc-mediated fragmentation of protected methyl 5-deoxy-5-iodo-D-pentofuranosides followed by an allylation of the intermediate aldehyde in the same pot. Th