Asymmetric dihydroxylation of the Cγ=Cδ bonds in trans‐configured α,β,γ,δ‐unsaturated esters, carbonate formation, and Pd0‐catalyzed deoxygenation of Cγ provided α,β‐unsaturated δ‐hydroxy esters. Protection and chain‐extension provided the corresponding α,β‐unsaturated ketones. Their asymmetric dihydroxylation in the presence of phenylboronic acid delivered dioxaborolanes. SmBr2‐mediated deoxygenation of Cα, followed by Narasaka–Prasad and Claisen–Tishchenko reductions, respectively, selectively provided monoprotected 1,3syn,3,5syn‐, 1,3syn,3,5anti‐, 1,3anti,3,5syn‐, and 1,3anti,3,5anti‐configured 1,3,5‐triols. Enones with a bulky OSiR3 group at Cδ were dihydroxylated with significantly poorer syn (vs. anti) selectivities. Dominating reagent control modulated by opposing (“mismatched case”) or enhancing (“matched case”) substrate control, respectively, might be responsible.