Toward the development of a general chiral auxiliary. 9. Highly diastereoselective alkylations and acylations to form tertiary and quaternary centers.
[reaction--see text] Enolates of a new camphor-derived lactam auxiliary are shown to monoalkylate with very high diastereoselectivity. A second alkylation occurs with reactive alkylating agents to afford quaternary centers also with high diastereoselectivity. In accord with a proposed model for diastereoselection, lithium and sodium enolates provide products with an opposite sense of asymmetric induction.
Boeckman
R K
RK
Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, USA. rkb@rkbmac.chem.rochester.edu
Boehmler
D J
DJ
Musselman
R A
RA
D000215:Acylation; D000478:Alkylation; D018360:Crystallography, X-Ray; D007202:Indicators and Reagents; D007769:Lactams / Q000138:chemical synthesis*; D008094:Lithium; D012964:Sodium; D013237:Stereoisomerism
D007202:Indicators and Reagents; D007769:Lactams; D008094:Lithium; D012964:Sodium