A number of 1‐substituted and 1,1‐disubstituted (E)‐4,5,5‐triethoxypent‐3‐en‐1‐ols (1) have been converted to perfluoroalkylated tetrahydrofurans and tetrahydropyrans in a selective fashion by 1‐iodoperfluoroalkane addition under radical conditions using sodium dithionite (Na2S2O4) as radical initiator. Direct perfluoroalkylation of 1 gave the former products only, and the yields were moderate (50–75 %), but when 1 was converted to corresponding 6‐substituted and 6,6‐disubstituted 2,3‐diethoxy‐5,6‐dihydro‐2H‐pyrans before perfluoroalkylation was carried out, the transformation turned out to be significantly more successful and afforded, as the only product, 6‐substituted and 6,6‐disubstituted 2‐ethoxy‐4‐(perfluoroalkyl)tetrahydropyran‐3‐ones in 77–100 % yield as stereoisomeric mixtures. Subsequent reduction of the keto group with sodium borohydride in ethanol was uneventful and completed the syntheses of a range of 4‐perfluorobutylated tetrahydropyran derivatives; the yields in this step were in the 81–94 % range. The best result was obtained with (E)‐2‐methyl‐5,6,6‐triethoxyhex‐4‐en‐2‐ol which was converted to a diastereoisomeric mixture of 2‐ethoxy‐6,6‐dimethyl‐4‐(perfluorobutyl)tetrahydropyran‐3‐ol in 85 % yield in three steps. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)