ChemInform Abstract: Stereoselectivity in the Formation of Unsaturated Wittig Products and Stereospecificity in Their Electrophile-Induced Cyclization to C-Glycosides.
Abstract
The reaction of the ribofuranose (I) with the phosphorane (II) leads to Z/E mixtures (IIIa) + (IIIb) depending on the reaction conditions, whereas only the E isomer (VII) is obtained from the mannofuranose (VI).
ChemInform Abstract
The reaction of the ribofuranose (I) with the phosphorane (II) leads to Z/E mixtures (IIIa) + (IIIb) depending on the reaction conditions, whereas only the E isomer (VII) is obtained from the mannofuranose (VI). Cyclization reactions of (IIIa), (IIIb), and (VII) with iodine provide the iodo compounds (IV), (V) and (VIII). In addition, the iodide (IV) can be transformed to the dianhydroheptonate (IX).