Bortezomib intermediates II

(αS)-α-Amino-N-[(1R)-1-[(3aS,4S,6S,7aR)-hexahydro-3a,5,5-trimethyl-4,6-methano-1,3,2-benzodioxaborol-2-yl]-3-methylbutyl]-benzenepropanamide Monohydrochloride is a Bortezomib (B675700) intermediate which is used in the evaluation of bone-targeted proteasome inhibitors for myeloma.