Dp. Becker et Dl. Flynn, PREPARATION OF TRIFLUOROMETHYL LACTOL DERIVATIVES VIA BASE-INITIATED CYCLOBUTANOL RING-OPENING TO A LATERALLY-LITHIATED TRIFLUOROMETHYL KETONE, Synlett, (1), 1996, pp. 57
Benzocyclobutenone derivatives 4 are converted to the corresponding tr
ifluoromethylcyclobutanols 5 by treatment with trifluoromethyltrimethy
lsilane in the presence of tetra-n-butylammonium fluoride. These trifl
uoromethylcyclobutanol derivatives are then treated with LiTMP in the
presence of aromatic aldehydes to afford trifluoromethyllactols 6 via
a laterally-lithiated trifluoromethylketone intermediate.