A new general protocol for the synthesis of O,Se-acetals using the seleno-Pummerer reaction has been developed, and their radical-based two- and three-component coupling reactions were studied. The three-component coupling employed the O,Se-acetal, cyclopentenone, and an allylstannane derivative, and enabled stereoselective installations of α-acyloxy alkyl and functionalized allyl groups to generate
The multiply oxygenated ABC-ring system of the dihydro-beta-agarofurans was synthesized by employing two highly stereoselective reactions. The quinidine-catalyzed Diels-Alder reaction between a chiral dienophile and 3-hydroxy-4-methyl-2-pyrone simultaneously installed the C2-stereogenic center and two contiguous tetrasubstituted carbon centers (C5 and C10) of the A-ring. After 12 additional transformations, the aldol reaction of the resulting spiral AC-ring cyclized the B-ring with stereoselective introduction of the C7- and C8-centers.
Facile synthesis of a carbohydrate derivative: 2-deoxy-2-C-methylene-D-erythro-pentono-1,4-lactone
作者:Christos Papageorgiou、Claude Benezra
DOI:10.1021/jo00202a003
日期:1985.1
Synthèse par aldolisation dirigèe des 2-dèsoxy-2-C-mèthylene-D-erythro- ET -D-thréo-pentoses