To obtain the acetyl-protected bicyclic boronic ester, the N-Cbz-protected bicycle derivative 10c was subjected to hydrogenation conditions, giving the free amine intermediate, which was subsequently reacted with AcCl to give the N-acetyl derivative 10d ( Scheme 3). Unfortunately, attempts to purify the free amine boronic ester intermediate for biological testing were unsuccessful, as purification conditions affected the boronic ester group.