Synthesis and Comparison of the Reactivity of Allyl Fluorides and ...

6.4.4 Preparation of Dimethyl 2-(4-(benzyloxy)but-2-enyl)malonate (147)
176
Chapter Six
The novel compound was prepared following
the method outlined by Hayashi et al. [17] A 50
cm 3 , two-necked round-bottom flask was
equipped with a magnetic stirring bar and
Rotaflo tap and attached to a Schlenk line. After flame-drying under high vacuum, the flask
was cooled and filled with nitrogen. The flask was charged with bis[�-chloro) bis(butenyl-
(1,2,3-�)-oxy)methyl)benzene]dipalladium (79 mg, 0.13 mmol) and anhydrous THF (5
cm 3 ). The reaction mixture was stirred at room temperature for 15 minutes, after which
PPh3 (136 mg, 0.52 mmol) and sodium dimethylmalonate (78 mg, 0.52 mmol) were added
and the mixture stirred overnight. The formed precipitate was filtered off and solvent
removed in vacuo to give the crude product which was purified by column chromatography
[hexane: ethyl acetate (70:30)], affording the product as a colourless oil (8 mg, 44 %). δH
2.59 (2H, dd, 3 JHH = 7.4 Hz, 3 JHH = 5.5 Hz, CH2CH(COOMe)2), 3.39 (1H, t, 3 JHH = 7.4 Hz,
CH(COOMe)2), 3.66 (6H, s, CH3), 3.88 (2H, d, 3 JHH = 4.7 Hz, OCH2CH), 4.40 (2H,
AB, 2 JAB = 13.3 Hz, CHAHBAr), 5.56- 5.67 (2H, m, -CH=CH-), 7.22-7.30 (5H, m, ArH).
m/z (EI + ) 292 ([M] + , 30 %).
6.4.5 Preparation of dimethyl 2-(1-(4-fluorobenzoyloxy)but-3-en-2-yl)malonate (150)
The novel compound was prepared following the
method outlined by Hayashi et al. [17] A 50 cm 3 ,
two-necked round-bottom flask was equipped with
a magnetic stirring bar and Rotaflo tap and
attached to a Schlenk line. After flame-drying under high vacuum, the flask was cooled and
filled with nitrogen. The flask was charged with bis[�-chloro-bis(butenyl-(1,2,3-�)-4-fluoro
benzoate] dipalladium (87 mg, 0.13 mmol) and anhydrous THF (5 cm 3 ). The reaction
mixture was stirred at room temperature for 15 minutes, after which PPh3 (136 mg, 0.52
mmol) and sodium dimethylmalonate (81 mg, 0.52 mmol) were added and the mixture
stirred overnight. The formed precipitate was filtered off and solvent removed in vacuo to
give the crude product which was purified by column chromatography [hexane: ethyl
acetate (70:30)], affording the product as a colourless oil (4 mg, 21 %). δH 3.25 (1H, m, Hd),
3.58 (1H, d, 3 JHH = 8.2 Hz, CH(COOMe)2), 3.65 (6H, s, CH3), 4.31 (1H, dd, 2 JHH = 11.3 Hz,
3 JHH = 6.3 Hz, He), 4.43 (1H, dd, 2 JHH = 11.3 Hz, 3 JHH = 5.9 Hz, Hf), 5.13 (1H, d, 3 JHH = 11.0