4.2. General procedure for the asymmetric aldol reaction of
TBS-protected hydroxyacetone with aromatic aldehydes
(Table 1)
To a stirred solution of catalyst (0.125 mmol, 25 mol %) in brine
(0.5 ml) and TBS-protected hydroxyacetone (5.0 mmol) was added
aldehyde (0.5 mmol) at room temperature under an atmosphere of
air. The reaction mixture was stirred at room temperature in
a closed system for an appropriate time until the reaction was
completed by monitoring TLC. Then the mixture was extracted
with CH2Cl2 (2 ml3) and the organic layers were dried over