2129
J. Am. Chem. SOC. 1981, 103, 2129-2131 Table 11. Aldol Condensations of I C and I d with Representative Aldehydes (Scheme 11)9 imide
R,CHO
Id Id Id Id
Me,CHCHO n-C,H,CHO CH,CHO C,H,CHO
a
ratio 11a:12aa 98.4:1.6 98.9~1.1 99.6:0.4 92.4:7.6
Determined by GLC (ref 13).
[a]"D
13 -42.1" -27.3" -45.8" -17.1"
(1.8)d (2.1)e (1.7)f (4.l)g
optical purity 13:14c 97.8:2.2 99.4:0.6 >99.9:
