3025
Y. Reyes, K. T. Mead
Paper
Synthesis
1H NMR (600 MHz, CDCl3): δ = 7.81 (d, J = 7.57 Hz, 2 H), 7.41–7.37 (m,
3 H), 5.64 (dd, J = 2.7, 7.4 Hz, 1 H), 4.16–4.09 (m, 2 H), 3.95–3.93 (m, 1
H), 3.67–3.64 (m, 1 H), 3.27 (dd, J = 7.4, 16.5 Hz, 1 H), 2.98 (dd, J =
2.68, 16.5 Hz, 1 H), 1.26 (t, J = 7.1 Hz, 3 H), 1.20 (t, J = 7.1 Hz, 3 H).
1H NMR (600 MHz, CDCl3): δ = 7.89 (s, 1 H), 7.81 (d, J = 7.7 Hz, 1 H),
7.53 (d, J = 7.2 Hz, 1 H), 7.39 (t, J = 7.8 Hz, 1 H), 4.7–4.75 (m, 1 H), 4.07
(q, J = 7.1 Hz, 2 H), 2.16–2.14 (m, 1 H), 2.10 (s, 3 H), 1.87–1.85 (m, 1
H), 0.98 (t, J = 7.1 Hz, 3 H).
13C NMR (150 MHz, CDCl3): δ = 164.8, 162.9, 130.2, 130.0, 129.3,
13C NMR (150 MHz, CDCl3): δ = 192.0, 170.6, 166.8, 138.3, 134.6,
127.5, 104.1, 102.0, 64.2, 59.7, 38.3, 15.1, 14.2.
132.7, 129.6, 128.1, 126.2, 61.6, 56.7, 38.6, 20.4, 20.3, 13.6.
HRMS (ESI-TOF): m/z [M – H]+ calcd for C15H17O4: 261.1121; found:
HRMS (ESI-TOF): m/z [M + Na]+ calcd for C15H15ClNaO5: 333.0506;
261.1145.
found: 333.0435.
Ethyl 2-Acetoxy-1-benzoylcyclopropanecarboxylate (4a)
Ethyl 2-Acetoxy-1-(3-methylbenzoyl)cyclopropanecarboxylate
(4e)
Vinyl acetate (0.20 mL, 2.18 mmol, 1 equiv), 2a (670.3 mg, 3.07 mmol,
1.4 equiv), Rh2(esp)2 (2.0 mg, 0.3 μmol, 0.001 equiv) gave a yellow oil;
yield of diastereomers: 305.8 mg (51%); β-lactone: 142.8 mg; Rf = 0.17
(CH2Cl2–hexane, 6:1).
1H NMR (600 MHz, CDCl3): δ = 7.89 (d, J = 7.3 Hz, 2 H), 7.55 (t, J = 7.3
Hz, 1 H), 7.45 (t, J = 7.3 Hz, 2 H), 4.81 (dd, J = 5.2, 6.9 Hz, 1 H), 4.01 (q,
J = 7.1 Hz, 2 H), 2.17–2.14 (m, 1 H), 2.09 (s, 3 H), 1.83–1.76 (m, 1 H),
0.93 (t, J = 7.1 Hz, 3 H).
Vinyl acetate (36.0 μL, 0.39 mmol, 1 equiv), 2e (126.7 mg, 0.55 mmol,
1.4 equiv), Rh2(esp)2 (0.4 mg, 0.5 μmol, 0.001 equiv) gave a clear oil;
yield of diastereomers: 30.6 mg (27%); β-lactone: 26.0 mg; Rf = 0.25
(CH2Cl2–hexane, 6:1).
1H NMR (600 MHz, CDCl3): δ = 7.71–7.69 (m, 2 H), 7.36–7.35 (m, 1 H),
7.34–7.31 (m, 1 H), 4.85–4.83 (m, 1 H), 4.04 (q, J = 7.1 Hz, 2 H), 2.16 (s,
3 H), 2.17–2.15 (m, 1 H), 2.09 (s, 3 H), 1.79–1.77 (m, 1 H), 0.95 (t, J =
7.1 Hz, 3 H).
13C NMR (150 MHz, CDCl3): δ = 193.1, 170.6, 167.2, 136.7, 132.9,
128.5, 128.4, 128.3, 128.1, 61.6, 56.6, 38.8, 20.5, 20.3, 13.6.
13C NMR (150 MHz, CDCl3): δ = 193.3, 170.6, 167.2, 138.3, 136.7,
133.7, 128.6, 128.3, 125.4, 61.6, 56.6, 38.9, 21.2, 20.5, 20.4, 13.6.
HRMS (ESI-TOF): m/z [M + Na]+ calcd for C16H18NaO5: 313.1052;
HRMS (ESI-TOF): m/z [M + Na]+ calcd for C15H16NaO5: 299.0895;
found: 299.0912.
found: 313.1010.
Ethyl 2-Acetoxy-1-(4-isopropylbenzoyl)cyclopropanecarboxylate
(4b)
Ethyl 2-Acetoxy-1-(4-methylbenzoyl)cyclopropanecarboxylate
(4g)
Vinyl acetate (23.5 μL, 0.25 mmol, 1 equiv), 2b (200.6 mg, 0.77 mmol,
3 equiv), Rh2(esp)2 (0.2 mg, 0.2 μmol, 0.001 equiv) gave a yellow oil;
yield of diastereomers: 59.3 mg (73%); β-lactone: 61.4 mg; Rf = 0.22
(CH2Cl2–hexane, 6:1).
1H NMR (600 MHz, CDCl3): δ = 7.86 (d, J = 8.1 Hz, 2 H), 7.30 (d, J = 8.1
Hz, 2 H), 4.81–4.79 (m, 1 H), 4.07 (q, J = 7.0 Hz, 2 H), 2.98–2.93 (m, 1
H), 2.14–2.12 (m, 1 H), 2.09 (s, 3 H), 1.78–1.75 (m, 1 H), 1.26 (d, J = 6.9
Hz, 6 H), 0.95 (t, J = 7.0 Hz, 3 H).
Vinyl acetate (30.0 μL, 0.33 mmol, 1 equiv), 2g (102.7 mg, 0.44 mmol,
1.4 equiv), Rh2(esp)2 (0.3 mg, 0.4 μmol, 0.001 equiv) gave a clear oil;
yield of diastereomers: 15.4 mg (16%); β-lactone: 18.5 mg; Rf = 0.19
(CH2Cl2–hexane, 6:1).
1H NMR (600 MHz, CDCl3): δ = 7.81 (d, J = 7.5 Hz, 2 H), 7.24 (d, J = 7.8
Hz, 2 H), 4.82–4.80 (m, 1 H), 4.06–4.05 (m, 2 H), 2.40 (s, 3 H), 2.15–
2.13 (m, 1 H), 2.09 (s, 3 H), 1.77–1.75 (m, 1 H), 0.98 (t, J = 7.1 Hz, 3 H).
13C NMR (150 MHz, CDCl3): δ = 192.5, 170.7, 167.3, 154.6, 134.3,
128.8, 128.5, 126.5, 126.4, 61.5, 56.5, 38.7, 34.2, 23.6, 23.5, 20.5, 20.1,
13.6.
13C NMR (150 MHz, CDCl3): δ = 192.5, 170.7, 167.4, 143.9, 133.9,
129.1, 129.0, 128.8, 128.4, 61.6, 56.4, 38.7, 21.6, 20.5, 20.2, 13.7.
HRMS (ESI-TOF) : m/z [M + Na]+ calcd for C16H18NaO5: 313.1052;
found: 313.1120.
HRMS (ESI-TOF): m/z [M + Na]+ calcd for C18H22NaO5: 341.1365;
found: 341.1306.
Ethyl 2-Acetoxy-1-(4-ethylbenzoyl)cyclopropanecarboxylate (4h)
Ethyl 2-Acetoxy-1-(3-bromobenzoyl)cyclopropanecarboxylate (4c)
Vinyl acetate (24.0 μL, 0.26 mmol, 1 equiv), 2h (191.3 mg, 0.7768
mmol, 3 equiv), Rh2(esp)2 (0.2 mg, 0.3 μmol, 0.001 equiv) gave a clear
oil; yield of diastereomers: 31.4 mg (40%); β-lactone: 47.8 mg; Rf =
0.23 (CH2Cl2–hexane, 6:1).
1H NMR (300 MHz, CDCl3): δ = 7.83 (d, J = 8.0 Hz, 2 H), 7.25 (d, J = 8.0
Hz, 2 H), 4.81 (dd, J = 5.3, 6.7 Hz, 1 H), 4.05 (q, J = 7.0 Hz, 2 H), 2.68 (q,
J = 7.6 Hz, 2 H), 2.15–2.12 (m, 1 H), 2.09 (s, 3 H), 1.78–1.75 (m, 1 H),
1.24 (t, J = 7.6 Hz, 3 H), 0.99 (t, J = 7.0 Hz, 3 H).
Vinyl acetate (0.05 mL, 0.54 mmol, 1 equiv), 2c (286.6 mg, 0.96 mmol,
1.7 equiv), Rh2(esp)2 (0.2 mg, 0.3 μmol, 0.0005 equiv) gave a yellow
oil; yield of diastereomers: 165.2 mg (86%); β-lactone: 36.7 mg; Rf =
0.20 (CH2Cl2–hexane, 6:1).
1H NMR (600 MHz, CDCl3): δ = 8.04 (s, 1 H), 7.86 (d, J = 7.5 Hz, 1 H),
7.68 (d, J = 7.6 Hz, 1 H), 7.33 (t, J = 7.7 Hz, 1 H), 4.77–4.75 (m, 1 H),
4.07 (q, J = 7.1 Hz, 2 H), 2.16–2.14 (m, 1 H), 2.10 (s, 3 H), 1.87–1.85 (m,
1 H), 0.98 (t, J = 7.1 Hz, 3 H).
13C NMR (75 MHz, CDCl3): δ = 192.5, 170.6, 167.3, 150.1, 134.1, 128.5,
127.9, 61.6, 56.4, 38.7, 28.9, 20.5, 20.1, 15.1, 13.6.
13C NMR (150 MHz, CDCl3): δ = 191.9, 170.5, 166.8, 138.5, 135.6,
131.0, 129.9, 126.6, 122.6, 61.6, 56.7, 38.6, 20.4, 20.3, 13.6.
HRMS (ESI-TOF): m/z [M + Na]+ calcd for C15H1579BrNaO5 (377.0001;
HRMS: m/z [M + Na]+ calcd for C17H20NaO5: 327.1208; found:
327.0902.
found: 376.9923.
Ethyl 2-Acetoxy-1-(4-fluorobenzoyl)cyclopropanecarboxylate (4i)
Ethyl 2-Acetoxy-1-(3-chlorobenzoyl)cyclopropanecarboxylate (4d)
Vinyl acetate (30.5 μL, 0.33 mmol, 1 equiv), 2i (232.8 mg, 0.99 mmol,
3 equiv), Rh2(esp)2 (0.3 mg, 0.4 μmol, 0.001 equiv) gave a clear oil;
yield of diastereomers: 39.3 mg (41%); β-lactone: 104.0 mg; Rf = 0.22
(CH2Cl2–hexane, 6:1).
Vinyl acetate (0.05 mL, 0.54 mmol, 1 equiv), 2d (309.7 mg, 1.23 mmol,
2.3 equiv), Rh2(esp)2 (0.4 mg, 0.5 μmol, 0.001 equiv) gave a yellow oil;
yield of diastereomers: 146.3 mg (87%); β-lactone: 60.3 mg; Rf = 0.30
(CH2Cl2–hexane, 6:1).
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2015, 47, 3020–3026