Abstract: Treatment of epoxides with bis(trimethylsilyl)‐selenide under strictly controlled conditions allows to isolate β‐hydroxy selenols which evidence an unexpected stability, taking into account their known propensity to afford diselenides. Also thiiranes and aziridines lead to functionalized selenols bearing a thiol and a N‐Ts‐ or N‐Boc‐protected amino moiety on β‐position. These selenols were stable enough to react with different electrophiles. Ab‐initio DF calculations on two suitable model systems, n‐propyl selenol and β‐hydroxy derivative, allow to ascribe the observed low tendency to oxidation to noncovalent interactions between the selenol moiety and the −OH group. [ABSTRACT FROM AUTHOR]