In our optimization studies, we had focused on reactions with α,β-unsaturated ethyl and benzyl esters. We sought to explore this cyclization reaction with other esters and related Michael acceptors (Scheme 3). We found that our reaction was productive with a variety of esters, including those with sterically bulky groups such as t-Bu and naphthyl (Scheme 3, Entries 1-3 and Entries 5-7). Interestingly, with substrate 19 (Scheme 3, Entry 3), using TBAF/CH2Cl2 in place of TMG/PhCl was essential for a productive reaction; a crystal structure of product 20 (CCDC 2301582) allowed us to unambiguously confirm its identity. This reaction was scaled from 0.2 mmol to 2.7 mmol (13.5-fold increase) without a loss of yield. We were pleased that other Michael acceptors such as α,β-unsaturated thioesters, α,β-unsaturated nitriles, and α,β-unsaturated tertiary amides were compatible with our optimized protocol (Scheme 3, Entries 4, 8, and 9). With an ester derived from menthol, chiral oxathiazinanes could be prepared (Scheme 4).