Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Reagents and conditions: (a)476n-BuLi, Et2O, −78 °C, then 60 °C, 2 h; (b) (PhSO2)2S, −78 °C, then rt, overnight; (c) TFA, DCM, rt, monitor by TLC until complete reaction; (d) LDA (4.1 or 2.1 equiv), THF, 0 °C, 2 h; (e) TFA, DCM, rt, then aq. NaHCO3 right after addition of TFA.
