Before we could begin exploring our envisioned intramolecular ring-opening of aziridines by tethered sulfamates, we had to develop robust protocols for starting material preparation (Scheme 2). While epoxy-sulfamates can be readily synthesized by mCPBA epoxidation of the corresponding alkene, alkenyl sulfamates were resistant to several existing aziridination protocols. Fortunately, alkenyl alcohols and alkenyl acetates were amenable to aziridination using Sharpless (Scheme 2A), Kürti (Scheme 2B), or Komatsu (Scheme 2C) reactions. In the case of aziridine acetates (Scheme 2A and 2B), carefully monitored hydrolysis gave aziridine alcohols, which were then converted into the corresponding sulfamates. Our laboratory has previously explored the ring-opening of epoxides and aziridines using both sulfamate and ditert-butylsilanol tethers. It is noteworthy that while ditert-butylsilanol epoxides and aziridines cyclize efficiently when treated with Lewis acids or Brønsted acids, the corresponding sulfamate substrates do not react well under these conditions. With epoxy-sulfamates, treatment with aqueous base gave clean and reproducible reactivity. Analogously, when aziridine sulfamate 1 was stirred with 1 equivalent of Bu4NOH•30H2O in a 1:1 mixture of CF3-toluene/H2O at room temperature, oxathiazinane 2 formed in an excellent yield of 82% (Scheme 3, Entry 1). A crystal structure of 2 allowed us to unambiguously assign its identity and relative stereochemistry (CCDC: 2274209). We wished to study the effect of adding substituents to the sulfamate nitrogen. Replacing H with a Me group did not dramatically affect the efficiency of cyclization (Scheme 3, Entry 2). With bulkier substituents such as p-methoxy-phenyl (Scheme 3, Entry 3), the yield of cyclization dropped, and the reaction time had to be extended by 16 h. We note that the mass balance of the reaction was excellent and was comprised of product and unreacted starting material. Cyclization reactions with p-methyl-phenyl and phenyl sulfamates were similarly efficient (Scheme 3, Entries 4-5). In contrast, N-cyclohexyl sulfamate 11 was completely resistant to cyclization (Scheme 3, Entry 6).