
TY  - JOUR
A1  - Cambie, RC 
A1  - Coddington, JM 
A1  - Milbank, JBJ 
A1  - Pausler, MG 
A1  - Rustenhoven, JJ 
A1  - Rutledge, PS 
A1  - Shaw, GL 
A1  - Sinkovich, PI 
T1  - Stereoselective Titanium-Mediated Aldol Reactions of Menthyl Acetate Enolates, and Allylations With Benzaldehyde
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1993
VL  - 46
IS  - 5
SP  - 583
EP  - 591
KW  - 
UR  - https://doi.org/10.1071/CH9930583 
N2  - The enolates of (+)- and (-)- menthyl acetate, formed by transmetallation from lithium with chloro ( cyclopentadienyl )bis(1,2:5,6-di-O-isopropylidene-&#945;-D-glucofuranosato-O3)titanium [ CpTi (DAGO)2Cl] (1), react with benzaldehyde from the Re-face with high stereoselectivities (95 and 92% diastereomeric excess) when 12-crown-4 is used during the transmetallation . Use of the chiral cyclopentadienyltitanium-&#945;,&#945;,&#945;&#945;,&#945;&#945;-tetraaryl-2,2-dimethyl-1,3-dioxolan-4,5-dimethanol (TADDOL) complex (3) gives lower diastereoselectivities (58 and 40%) but the Si -face of benzaldehyde is attacked preferentially. Transmetallation of the 2-methylprop-2-enyl moiety to CpTi (DAGO)2Cl gives an allyltitanium reagent (2) which reacts with benzaldehyde from the Re-face with 88% enantiomeric excess. 
ER  -

