Answer to Question #295452 in Organic Chemistry for feyintola

Question

GIVEN

(A) PhCHO

(B) CH2(CO2Et)2

(c) PhCOCH3

DESIGN TWO ROUTE FOR THE SYNTHESIS OF PhCOCH2CH(Ph)CH(CO2Et).

(1)EACH OF THE ROUTE SHOULD GO THROUGH THE MICHAEL ADDITION REACTION.

(2) COMMENT ON THE SUITABILITY OF EACH ROUTE.

Answer 1

The two route for the synthesis of PhCOCH2CH(PH)CH(CO2Et)

1)The Michael reaction or Michael addition is the nucleophilic addition of a carbanion or another nucleophile^[1][2] to an α,β-unsaturated carbonyl compound containing an electron withdrawing group. It belongs to the larger class of conjugate additions. This is one of the most useful methods for the mild formation of C–C bonds.^[3] Many asymmetric variants exist.^[4][5]

2)In this scheme, R and R' on the nucleophile (the Michael donor) represent electron-withdrawing substituents such as acyl and cyano groups, which make the adjacent methylene hydrogen acidic enough to form a carbanion when reacted with the base, B:. The R" substituent on the activated alkene, also called a Michael acceptor, is usually a ketone, which makes the compound an enone, but it can also be a nitro group or a sulfonyl methyl fluoride.