Ketones, chiral reaction with organolithium

For aU the chiral intermediates above mentioned (253, 257 and 258) the reaction with prochiral electrophiles (aldehydes or differently substituted ketones) gave a c 1 1 mixture of diastereomers so, as occurred in other chiral functionalized organolithium compounds, the asymmetric induction is practically non-existent. 

The reaction of organolithiums 591 and 592 with aldehydes and ketones took place at low temperatures (—78 to 0°C) to generate the corresponding alcohols (50-100% yield)824,865,872,873,890 893. Diastereoselective addition took place with chiral aldehydes,... 

Chiral boronic esters react with organolithium reagents to form diorganylalkoxyboranes (borinic esters). Subsequent reaction with the anion of dichloromethyl methyl ether then yields chiral ketones by rearrangement of both of the groups on boron (Scheme 42). No racemization is observed in this sequence and alkyl-, aryl- or alkynyl-lithium reagents can be used. 

Ketones, including chiral a-an organolithium reaction with morph Addition reactions. A route with quinones derivatives. ... 

Ketones, including chiral a-amino ketone derivatives, are also produced from the organolithium reaction with morpholine amides. 

This chiral base can now choose to remove from the pyrrolidine substrate just one of the enantiotopic protons adjacent to nitrogen, and form a chiral, enantiomerically enriched organolithium. The stereochemistry of the organolithium is preserved through its reactions with electrophiles such as the ketone shown here. 

---