Toluene → methyl 2-(2-bromo-E-ethenyl)-delta-oxobenzenepentanoate

Temperatur

120 °C

To 10ml of toluene was added 6.0g (9.9 mol) of trans-1,2-bis(tri-n-butylstannyl)ethylene, which was prepared according to the procedure of Corey, et al., J. Org. Chem., 40, 3788 (1975), and 0.5g (1.8 mmol) of the product of Example 3. To the solution was then added 0.040g (.035 mmol) of 2 mole% tetrakis(triphenylphosphine)palladium(O) and the solution was degassed with argon. The reaction mixture was heated under argon for 1 hour at 120°C. (oil bath). Thereafter, the reaction mixture was cooled to -20°C. To the reaction mixture was added dropwise with stirring, a solution of 1.5ml (29.1 mmol) of Br2 in 30ml of CCl4 until thin layer chromatography of the reaction mixture indicated that all of the product of Example 3 was consumed. The volatile components were removed in vacuo. The residue was flash chromatographed on a silica gel column. Sequential elution with hexane, 5% diethyl ether in hexane, and 10% diethyl ether in hexane produced 0.48g of the titled product. The product was triturated with cold hexame to give a white solid, m.p. 52-55°C.

1. customwas prepared
2. customthe solution was degassed with argon
3. temperatureThereafter, the reaction mixture was cooled to -20°C
4. additionTo the reaction mixture was added dropwise
5. customwas consumed
6. customThe volatile components were removed in vacuo
7. customchromatographed on a silica gel column
8. washSequential elution with hexane, 5% diethyl ether in hexane, and 10% diethyl ether in hexane

ORD-Eintrag

ord-c70e537ecc314f84840ede374b5c792c

Quelldatensatz

uspto-grants-1989_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04855324