O-acetyl quinidine

Charge the second flame dried and argon flushed two-necked flask with O-acetyl quinidine, dissolve in ether (8 mL), and cool to 0°C. 

The use of 1 with m-oxocarboxylic acids 21, in the presence of O-acetyl quinidine (10 mol%, 22, NR3) to produce chiral p-lactones (23), has been demonstrated by Romo.11... 

Subsequently, Romo et al. studied an intramolecular nucleophile (O-acetyl quinidine, O-Ac-QD) catalysed aldol-lactonisation (NCAL) process of achiral acid-aldehydes (R = R ) promoted by a modified Mukaiyama reagent (Scheme 15.10) and EtsN, providing p-oxoketenes in situ, leading to a variety of novel p-lactone-fused bicyclic systems. This process was then extended to keto-acid substrates and more recently to racemic substrates (R t R ) demonstrating the utility of the Cinchona alkaloid catalysts O-TMS quinidine (O-TMS-QD) and O-TMS quinine (O-TMS-Q), in doubly diastereoseleetive NCAL reactions. ... 

P-lactone motif. O-Acetyl quinidine 73 or quinine were found to be effective catalysts, with acid activation achieved by the use of modified Mukaiyama reagents 75 or 76. The former provided improved reaction efficiency with a range of bicyclic-p-lactones produced exclusively as the cis-diastereomer in good yield (typically >70%) and excellent enantiomeric excess (typically >90% ee) [41]. 

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