References and Notes
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<A NAME="RD25707ST-2">2</A> For some examples of isoxazolidines, see:
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<A NAME="RD25707ST-8">8</A> This is considered to be much lower than typical loadings:
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<A NAME="RD25707ST-9">9</A>
Typical Procedure: A solution of alkene 5 (207 mg, 0.67 mmol), Grubbs second generation catalyst (11 mg, 2 mol%) and methyl
acrylate (182 µL, 2.02 mmol) in CH2Cl2 (2 mL) was heated at reflux under nitrogen for 3 h. The mixture was then cooled and
the volatiles were removed under reduced pressure. The mixture was purified by column
chromatography on silica gel eluting with 10-20% EtOAc in hexane to give the ester
7a as a solid (237 mg, 97%). 1H NMR (300 MHz, CDCl3): δ = 7.65 (m, 4 H, Ar), 7.39 (m, 2 H, Ar), 7.26 (m, 3 H, Ar), 6.99 (dt, J = 6.5, 15.5 Hz, 1 H, H3), 5.87 (d, J = 15.5 Hz, 1 H, H2), 5.31 (t, J = 6.5 Hz, 1 H, H6), 3.72 (s, 3 H, OMe), 2.32 (m, 3 H, H4, H5), 2.00 (m, 1 H, H5).
<A NAME="RD25707ST-10">10</A>
Typical Procedure: Hydrazine hydrate (78 µL, 1.6 mmol) was added to a solution of phthalimide 7a (195 mg, 0.53 mmol) in CH2Cl2 (2 mL). The mixture was stirred for 15 min, and then filtered through a pad of celite
to remove the copious colourless precipitate. The filtrate was evaporated to give
the oxazine 10a as an oil (122 mg, 98%). 1H NMR (300 MHz, CDCl3): δ = 7.23 (m, 5 H, Ph), 5.30 (br s, 1 H, NH), 4.55 (dd, J = 11.2 Hz, 1 H, H6), 3.70 (s, 3 H, OMe), 3.44 (m, 1 H, H3), 2.45 (dd, J = 16.8, 4.7 Hz, 1 H, CHHCO2Me), 2.37 (dd, J = 16.8, 8.5 Hz, 1 H, CHHCO2Me), 1.50-2.00 (m, 4 H, H4, H5). Compound 10c was prepared analogously. 1H NMR (300 MHz, CDCl3): δ = 7.80 (m, 2 H, Ar), 7.50 (m, 3 H, Ar), 7.20 (m, 5 H, Ar), 6.40 (br s, 1 H, NH),
4.59 (dd, J = 10.7, 2.3 Hz, 1 H, H6), 3.59 (ddt, J = 10.9, 8.8, 2.8 Hz, 1 H, H3), 3.14 (dd, J = 14.5, 9.0 Hz, 1 H, CHHSO2Ph), 3.03 (dd, J = 14.5, 3.0 Hz, 1 H, CHHSO2Ph), 1.50-1.90 (m, 4 H, H4, H5).
<A NAME="RD25707ST-11">11</A>
The corresponding alcohol is prepared by the reaction between styrene oxide and vinyl
magnesium bromide in Et2O. We thank Professor David Knight, University of Cardiff, for this procedure.
<A NAME="RD25707ST-12">12</A> For a discussion of cross-metathesis of different classes of alkenes, see:
Chatterjee AK.
Choi TL.
Sanders DP.
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Banwell MG.
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