. Author manuscript; available in PMC: 2016 Aug 19.

Published in final edited form as: J Am Chem Soc. 2015 Aug 7;137(32):10336–10345. doi: 10.1021/jacs.5b06126

Table 1.

Cyclization Reactions in the Absence of Added External Nucleophile

Entry	Substrate	Conditions	Products, % yield, (pyranose conformation, method)
1	13	Tf₂O, TTBP, −72 °C	28, 45% (⁴C₁, X-ray, NMR) + 29, 25% (¹S₅, X-ray, NMR)
2	15	TMSOTf, TTBP, −20 °C	28, 70% + 29, 25%
3	18	Tf₂O, TTBP, −72 °C, 1-octene	30, 52% (⁴C₁, X-ray, NMR), + 31, 20% (¹S₅, NMR)
4	21	Tf₂O, TTBP, −72 °C, 1-octene or β-pinene	32, 20% (¹S₅, X-ray, NMR),
5	27	TMSOTf, TTBP, −20 °C	32, 92%