The (E)‐ and (Z)‐terpene‐based aldehydes 6b and 6c with a silyl ether function in the γ‐position were prepared and investigated in boron‐mediated asymmetric Evans aldol reactions. Screening experiments of chiral N‐acylated oxazolidinones 7, which are conveniently accessible from 5‐methyl‐5‐hexenoic acid and Evans oxazolidinone auxiliaries, with various boron triflates and terpenoid neral (Z)‐6a as aldehyde component, provided conditions in which highly selective formation of syn‐aldol adduct 5a occurred and competing C=C double bond isomerization to 10 was completely suppressed. Applying the optimized conditions to O‐silylated aldehydes 6b and 6c and N‐acyloxazolidinone derivative (R)‐7a confirmed the syn‐selectivity and gave the appropriate products syn‐5b,c and syn‐21b,c in good yields. In the case of neral‐derived syn adduct 5a, the configuration of the new stereogenic centers C‐2/C‐3 could be assigned as (2R,3S).