... Soon thereafter, Cresson et al. ... ii) KHMDS, ether, −78 °C to rt; (d) (n = 1, R = H or CH 3 ) (method i) KHMDS, TIPSOTf, ether, −78 °C to rt; (e ... The high E-stereoselectivity observed in the 2-bromo series is consistent with the transition state analysis (Scheme 7). It is noteworthy that a ...