Sec-Butyl crotonate

A. sec-Butyl crotonate. In a 2-1. round-bottomed flask are placed 258 g. (3 moles) of crotonic add (Note 1), 370 g. (5 moles) of sec-butyl alcohol in which has been dissolved 6-7 ml. of concentrated sulfuric acid, and 300 ml. of benzene. A few boiling chips are added, and the flask is fitted with a suitable water separator (Note 2) in the top of which is placed a reflux condenser. The mixture is heated under reflux for about 12 hours or until no further separation of aqueous phase occurs. About 65 ml. of water is collected. The cooled reaction mixture is diluted with 200 ml. of ether, washed with 10% sodium carbonate solution... 

Esterification, of cyanoacetic acid, 41, 5 of gluconolactone, 41, 79 of tetraacetylgluconic acid, 41, 80 of a-d-unsaturated acids, 41, 62 preparation of sec-butyl crotonate by, 41, 60... 

After the addition has been completed, the solution is heated under reflux for 10-15 minutes. The flask is now surrounded by an ice and water bath, and stirring is continued for 15 minutes (Note 4). From a graduated dropping funnel, a solution of 56.8 g. (0.4 mole) of sec-butyl crotonate (Note 5) in 400 ml. of dry ether is then added dropwise during a period of about 3 hours (Note 6) while the reaction mixture is effectively stirred and cooled in the ice bath. After the addition of the ester solution is complete, the reaction mixture is stirred in the ice bath for an additional 15 minutes. The ice bath is then removed, and stirring of the grayish brown solution is continued at room temperature for 1 hour. 

The submitter has, by either cuprous chloride-catalyzed or uncatalyzed reactions, prepared a variety of 3-methyl-substituted fatty acids from the adducts of sec-butyl crotonate and other... 

Under usual Grignard conditions, n-butylmagnesium bromide adds largely 1,4 to sec-butyl crotonate to give sec-butyl 3-methylheptanoate in the yield indicated. ... 

The yields of 1,4-addition products from sec-butyl crotonate and Grignard reagents are improved by CuCl-catalysis provided that the catalyst is added to the Grignard reagent in small portions concurrently with the ester soln.— E n-Butylmagnesium bromide from n-butyl bromide and Mg in ether treated at 0 with ethereal scc-butyl crotonate and simultaneously with 1.4 mole-% CuCl in small portions over a period of 3 hrs. scc-butyl 3-methylheptanoate. Y 80 to 85%. F. e. s. J. Munch-Petersen and V. K. Andersen, Acta Chem. Scand. 15, 271, 293 (1961) cf. Org. Synth. 41, 60 (1961). 

Crotonic acid, esterification with sec-butyl alcohol, 41, 60 Crystal Violet, from condensation of oxalyl chloride with dimethyl-aniline, 41, 2-4... 

Reaction of ethyl crotonate and nitroethane in the presence of the basic 1,8-diaza-bicyclo[5.4.0]undec-7-ene (DBU) led to nitro-ester 3.49 in 74% yield.31 Catalytic hydrogenation of the nitro group and acid hydrolysis produced 3-methyl-4-amino-butanoic acid, 3.50. Choosing different conjugated esters as starting materials led to formation of 3-ethyl- (59% overall yield) 3-propyl- (51% overall yield) 3-isopropyl-(62% overall yield) 3-butyl- (56% overall yield) 3-sec-butyl- (60% overall yield) 3-isobutyl- (58% overall yield) and, 3-r-butyl-4-aminobutanoic acid (31% overall yield).31 The yields observed in this study clearly show that conjugate addition of nitro enolates is a synthetically useful process. 

Poly(f/ /-r-butyl crotonate) Chromatography 1,1,3,3,3,-hexafluoro- SEC, p-styraged, analytical 3324... 

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