The reaction of organometallic derivatives of monosaccharides with aldehydes catalyzed with BF3·OEt2 was studied. A significant difference in reactivity between the pyranosidic and furanosidic allyltins was noted. The former reacted readily with aldehydes affording precursors of higher carbon sugars with very high stereoselectivity, while the latter underwent rearrangement with elimination of the stannyl
Prebiotic carbohydrate synthesis: zinc–proline catalyzes direct aqueous aldol reactions of α-hydroxy aldehydes and ketones
作者:Jacob Kofoed、Jean-Louis Reymond、Tamis Darbre
DOI:10.1039/b501512j
日期:——
Znâproline catalyzed aldolisation of glycoladehyde gave mainly tetroses whereas in the cross-aldolisation of glycoladehyde and rac-glyceraldehyde, pentoses accounted for 60% of the sugars formed with 20% of ribose.
Stereoselective epoxidation of divinylmethanol: A synthetic approach to the pentitols
作者:David Holland、J. Fraser Stoddart
DOI:10.1016/s0008-6215(00)81036-8
日期:——
-butyl hydroperoxide with catalytically active Ti 4+ , V 5+ , or Mo 6+ complexes are employed as epoxidation reagents. However, the diastereoselectivities characterising the epoxidations and the regioselectivities governing the epoxide-ring openings are not sufficiently high to constitute an attractive synthesis of either ribitol, dl -arabinitol, or xylitol from divinylmethanol.