... Synthesis 2004(3 ... The optical rotations were measured on a Jasco P-1010 polarimeter using the sodium D line at 589 nm. ... The mixture was stirred at rt for 4 h, then neutralized with 2 M HCl (50 mL, 0.10 mol), extracted with Et 2 O (3 × 40 mL), the combined extracts were washed ...