scheme2

Scheme 2. Gram-scale Reaction and Product Derivatization. [a] Reaction conditions:1 (0.4 mmol), DDQ (0.44 mmol), H1 (0.6 mmol). Ee was determined by chiral HPLC analysis. Isolated yield. The specified temperature for each example is for the second step (reduction). [b] Run with 0.5 mol% of catalyst. [c] Run with 1 mol% of catalyst. [d] Run with 2 mol% of catalyst. [e] Run with 5 mol% of catalyst.