CHIRALITY TRANSFER FROM LACTIC-ACID DERIVATIVES VIA [3,3] SIGMATROPICREARRANGEMENTS

Enantiomerically pure lactaldehyde 4 was converted via stereoselective Wittig reactions to the E or Z enoates 5 or 6. These were then transf ormed into the E and Z allylic trichloroimidates 9 and 13, respectivel y. Thermal [3,3] sigmatropic rearrangement of 9 and 13 yielded 10 and 14, respectively, thus providing a simple entry to both enantiomers of 1,2-amino alcohol derivatives from a single chiral precursor.