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.
Prins cyclization approach. a, 1: Me2CuLi·LiBr, Et2O, -78°C (81%, 5:4, Z/E); 2: BnBr, NaH, DMF (91%). b, Diisobutylaluminum hydride, CH2Cl2, -78°C (40% of 22a plus Z isomer 22b). c, TPAP, 4-Å sieve, NMO, CH2Cl2 (89%). d, Me2AlCl, CH2Cl2, 0°C (8% of 40, 27% of 41, and 18% of 42).
