286476-36-6Relevant articles and documents
Structural modification of carbohydrates via functionalised organolithium intermediates: EPC preparation of branched-chain functionalised sugars
Soler, Tatiana,Bachki, Abderrazak,Falvello, Larry R.,Foubelo, Francisco,Yus, Miguel
, p. 493 - 517 (2000)
The reductive opening of epoxides 1, 9, 13 derived from D-glucose and 18 derived from D-fructose using lithium and a catalytic amount of 4,4'-di-tert-butylbiphenyl (DTBB) in THF at -78°C allows the formation of β-oxido organolithium derivatives (2, 10, 14 and 19), which, by reaction with different electrophiles [H2O, D2O, Me3SiCl, PhCHO, Me2CO, Et2CO, (CH2)5CO, CO2] at the same temperature yields, after hydrolysis with water, the expected branched-chain functionalised carbohydrates. An alternative route for compound 11, derived from the epoxide 9, consists of the deprotonation of the chlorohydrin 12 followed by the same protocol of lithiation-reaction with an electrophile. The application of this methodology to the oxetane 4 allows compound 6 to be obtained through the corresponding γ-functionalised organolithium intermediates 5. Finally, the addition of the dianions 25 (resulting from the DTBB-catalysed lithiation of phthalan and isochroman) to the ketones 8 and 23, derived from D-glucose and D-fructose, respectively, allowed the stereoselective functionalisation at the 3-position of the sugars, giving the corresponding diols 26 and 27, which can cyclise to the corresponding heterocycles 28 and 29, respectively, under Mitsunobu reaction conditions. Copyright (C) 2000 Elsevier Science Ltd.