Low-Valent Titanium Induced Carbonyl Coupling Reactions

Dimestrole (7), a precursor of diethylstilbestrol is readily prepared from the ketone (6)[5,6]
O
6
12
OMe
CH 3
TiCl 3/LiAlH 4/THF
95 %
MeO
3.1.1 Synthesis of Strained Alkenes
7
CH 3
C
H 3
The coupling of ketones with low-valent titanium reagent to form alkenes is generally effective
for simple ketones. In sterically hindered ketones, however, the yields are generally low (table
2) and alternative synthetic routes have been unsuccessful for some of these compounds.
OMe