To our delight, subjecting redox-active esters to the photoredox conditions followed by pinanediol delivered Ala B (12) with no detectable epimerization ( 19 F NMR of the Mosher amide) and in excellent yields. The optimized protocol was then applied to the synthesis of Boc and Fmoc-protected Ala B in the form on BPai and BMIDA esters. BMIDA ester 15 was also readily converted into a free acid suitable for oligopeptide/protein synthesis (vide infra).