Esters, conjugated, reaction with

Aziridines. Aziridine-2-carboxylic esters are formed at room temperature by reaction of conjugated esters with NsONHCOOEt in the presence of CaO. Similarly, nitroalkenes react in the same way.- ... 

Michael reaction. For conducting a Michael reaction of (3-ketoesters with conjugated esters and ketones at room temperature under solvent-free conditions, triflic acid is useful. 

The Tebbe reagent is quite useful in that it reacts with the carbonyl of esters to give vinyl ethers. Pine showed that 683 reacted with methyl benzoate to give an 81% yield of 1-methoxy-l-phenylethene. O Similar reaction of lactone 686 with 683 gave the exo-methylene vinyl ether 687 in Holmes synthesis of (+)-laurencin.571 The Tebbe reagent also reacts with conjugated esters via 1,2-addition to give the vinyl ether. ... 

Table 11.15. Enantioselectivity in the Diels-Alder reaction of Cyclopentadiene with Conjugated Esters Derived from Chiral Alcohols...

Reaction with conjugated aHenic ketones and esters. Lithium dimethyl cuprate adds 1,4- to these unsaturated systems, and the intermediate lithium enolate a can be alkylated, as in related reactions (equation I). This reaction thus permits... 

A chiral precursor of a special type is sulfoxide 48, used in a synthesis of (+)-boronolide (Scheme 2.10) [33aj. Acylation of its hthium anion with conjugated ester 49 gave P-ketosulfoxide 50, which was stereoselectively reduced under chelation control to P-hydroxy sulfoxide 51. Oxidative funtionahzation of the olefinic bond (five steps) furnished triacetate 52, stiU containing the stereogenic sulfoxide moiety. The latter was eliminated by means of a Pummerer reaction, which afforded... 

R—Cu—BF3 Conjugate addition including successful reaction with acrylate esters and acrylonitriles. Sn2 displacement of allyl halides. 

Maruoka and coworkers [65] also reported the total synthesis of (+) mono-morine (127) using a phase-transfer-catalyzed conjugate addition of glycine ester 128 to Michael acceptor 129 as an early key step in the synthesis sequence. Monomorine (127) is a bicyclic amine, known to be the trail pheromone of Monomorium pharanois [66]. The conjugate addition product 131 was subjected to an intramolecular reductive amination and acetal hydrolysis in one pot reaction with Hantzsch ester 132 and trifluoroacetic acid in aqueous... 

---