Chemistry Commons^™

Glycals : An Extended Study Of The Ferrier-Dimerization, Andreas H. Franz

University of the Pacific Theses and Dissertations

C-linked disaccharides were synthesized from 3,4,6-tri-O-acetyl-D-glucal 1 (1,5- anhydro-3,4,6-tri-O-acetyl-1,2-dideoxy-D-arabino-hex-I-enopyranose), 3,4,6-tri-O- acetyl-D-galactal 2 (1,5-anhydro-3,4,6-tri-O-acetyl-1,2-dideoxy-D-lyxo-hex-1- enopyranose) and 3,4-di-O-acetyl-L-fucal 3 (1,5-anhydro-3,4-di-O-acetyl-1,2,6-tri-deoxy- L-lyxo-hex-1-enopyranose) under Lewis acid catalysis (Scheme 1) and compound 4 was further derivatized at the double bond. Dihydroxylation of the glucose dimer 4 gave high allo-diastereoselectivity. The reactions used in the derivatization of 1 were subsequently applied to 2 and 3. The overall yield of 3 was improved to 70 %. All three glycals (10% solution in toluene) reacted quickly with boron trifluoride to give dimerization products in 40-60% yield. Futile attempts at de-O-acetylation of the 2',3'-unsaturated dimer revealed the necessity of …