To overcome these biases, we evaluated compound 4e as a model substrate under common organic transformation conditions. We included highly acidic (TFA and anhydrous HCl), basic (LiOH), oxidative (Dess-Martin periodinane and 30% aq H2O2), and reductive agents (H2 -Pd/C and LiAlH4), irradiation (at 365 and 450 nm), and air. The experiment included mixing the compound 4e and indicated reagents at low (0 °C), ambient (24 °C), and elevated (60 °C) temperatures (or irradiation at the corresponding wavelengths) for 2 h, work-up of the reaction mixture. Then, the recovery yields were measured by quantitative 1 H NMR spectroscopy against a control sample of 4e. The results have been depicted as a radar diagram (Figure ). It is apparent that the 3,3-diFox moiety is compatible with most common reaction conditions at 0 °C and 24 °C. As expected, elevated temperature was detrimental for the relative recovery ratio (42-88%); in this case, significant decomposition was observed in the presence of HCl and LiAlH4 (but not LiOH). Notably, dehalogenation was the main decomposition pathway in the presence of reductants: while the oxetane fragment remained virtually intact, significant amounts of defluorinated products were detected (up to 11% for catalytic hydrogenation and 80% for LiAlH4). Finally, the stability of the 3,3-diFox fragment was illustrated by a five-year on-shelf storage with no detected loss of the sample quality (see the Supporting Information). The observed results correlate with previously reported data on other 3,3-substituted oxetanes. This effect was typically referred to reduced ring strain and/or sterically hindered access to C-O σ* antibonding orbital; these explanations are less pertinent for the 3,3-diFox fragment. Structural and electronic properties. An X-Ray diffraction study of (S*,S*)-4d and comparison of the obtained results with the CCDC data for oxetane, cyclobutane, and 3,3-difluorocyclobutane derivatives revealed several structural features of the 3,3-diFox moiety (Figure ). While the gem-CF2 or O fragments had minor effects on the valent angles 1 and 2 as compared to the parent cyclobutane scaffold (1-2° difference), ring puckering angle θ was affected significantly. Thus, introducing oxygen atom to the cyclobutane ring led to its significant flattening (θ = 26.9° and 6.9° for cyclobutane and oxetane, respectively), while gem-difluorination slightly increased puckering (26.9° and 29.7°, respectively). For the oxetane core, the latter effect of gem-difluorination was even more pronounced: the θ value was increased by 10°. (DFT/PBE0/ma-def2-TZVP). (D) Dipole moments calculated for parent cyclic compounds 16a-d.