Improved Synthesis of α‐L‐Fuc(1 → 4)‐β‐D‐GlcNAc (‐)‐( III) and α‐L‐Fuc(1 → 6)‐β‐D‐GlcNAc (‐)‐(I) Building Blocks: A Convergent Strategy Employing 4‐O → 6‐O Acetyl Migration. NOE Data of the Protected α‐1,4‐Linked Disaccharide.