... The Journal of Organic Chemistry. ... First, coupling of the acceptor 5 and trichoroacetimidate 8 in dichloromethane with TMSOTf as promoter afforded the β-(1 → 4)-linked disaccharide 12 in 81% yield (Scheme 5). The chemical shifts of H-1′ (δ 5.49 ppm, J 1′,2′ 8.2 Hz) and ...