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Enantioface differentiating Michael reaction of ethyl acetoacetate with alkylidenemalonates via chiral enamine

✍ Scribed by Kiyoshi Tomioka; Kōsuke Yasuda; Kenji Koga


Publisher
Elsevier Science
Year
1986
Tongue
French
Weight
253 KB
Volume
27
Category
Article
ISSN
0040-4039

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✦ Synopsis


Utilizing the I_-valine-based chiral lithioenamine (5) of ethyl acetoacetate (l), enantioface differentiating Michael reaction with alkylidenemalonates (2) gave, after decarboxylation, B-substituted g-keto esters (3) in a fair to good enantiomeric excess. Kinetic diastereoenrichment of the initial Michael adducts (7) was also studied. Combination of both processes provides the procedure for the synthesis of 3 in 55-93% ee.