... Tetrahedron Letters. ... acids can be synthesized in an enantiomerically pure form by the phase-transfer catalytic alkylation of substrate 2. In this letter, we wish to ... alkylation of 2 with benzyl bromide 3 (R 1 =OBn) (1.2 equiv.) 3 in toluene–50% KOH aqueous solution (volume ratio=3 ...