Synthesis of C-2 Methylene O- and C-Glycosides and Sugar Derived α-Methylene-δ-valerolactones from C-2-Acetoxymethyl Glycals
作者:Anuradha Gupta、Yashwant D. Vankar
DOI:10.1016/s0040-4020(00)00775-4
日期:2000.10
C-2-Methylene O- and C-glycosides are readily synthesized from C-2-acetoxymethyl glycals using Nafion-H(R), montmorillonite K-10, LiClO4 (0.07 M) in dichloromethane and Pd(PPh3)(4) as catalysts. Exclusive alpha or beta selectivities have been observed with various primary, secondary and tertiary alcohols, phenols and diethyl malonate. Further, C-2-acetoxymethyl glycals are also converted into corresponding alpha -methylene-delta -valerolactones in good yields in one step using m-CPBA in the presence of BF3. Et2O. (C) 2000 Elsevier Science Ltd. All rights reserved.
Kast, Juergen; Hoch, Monika; Schmidt, Richard R., Liebigs Annalen der Chemie, 1991, # 5, p. 481 - 485
作者:Kast, Juergen、Hoch, Monika、Schmidt, Richard R.
DOI:——
日期:——
KAST, JURGEN;HOCH, MONIKA;SCHMIDT, RICHARD R., LIEBIGS ANN. CHEM.,(1991) N, C. 481-485
作者:KAST, JURGEN、HOCH, MONIKA、SCHMIDT, RICHARD R.
DOI:——
日期:——
GIESE, BERND;HOCH, MOHIKA;LAMBERTH, CLEMENS;SCHMIDT, RICHARD R., TETRAHEDRON LETT., 29,(1988) N 2, 1375-1378
作者:GIESE, BERND、HOCH, MOHIKA、LAMBERTH, CLEMENS、SCHMIDT, RICHARD R.
DOI:——
日期:——
Synthesis of methylene bridged C-disaccharides
作者:Bernd Giese、Monika Hoch、Clemens Lamberth、Richard R. Schmidt
DOI:10.1016/s0040-4039(00)80300-7
日期:1988.1
Addition of glycosyl radicals to the α-methylene lactones 8 obtained from the corresponding glycopyranosyl phenylsulfoxides 5a,b in convenient two step procedures provides methylene bridged C-disaccharides in high diastereoselectivities. Thus, after reduction of the lactone moiety the methylene bridged analogs 9–11 of kojibiose, ristobiose, and α-L-fucopyranosyl (1→2)-D-galactose, respectively, were