PAPER
α-Carboxy β-Lactones
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(±)-3-[(tert-Butylsulfanyl)carbonyl]-4,4-dimethyloxetan-2-one
13C NMR (CDCl3): δ = 16.6, 17.4, 29.5, 31.7, 49.8, 65.9, 78.6,
163.0, 189.4.
MS: m/z (%) = 186 (2, [M+ – CO2]), 143 (5), 130 (8), 97 (100), 69
(12), 57 (28).
HRMS: m/z [M + H]+ calcd for C11H19O3S: 231.1055; found:
231.1053.
(3e)
Using 2a (233 mg, 1.5 mmol) gave 3e as a colorless oil (173 mg,
53%); Rf = 0.43.
IR (ATR): 1819, 1666 cm–1.
1H NMR (CDCl3): δ = 1.40 (s, 9 H, CH3), 1.50 (s, 3 H, CH3), 1.59
(s, 3 H, CH3), 4.20 (s, 1 H, CH).
(3S,4S)-4-Benzyl-3-[(tert-butylsulfanyl)carbonyl]oxetan-2-one
(6a)
13C NMR (CDCl3): δ = 21.8, 27.4, 29.3, 49.6, 69.6, 79.8, 162.9,
198.7.
MS: m/z (%) = 172 (2, [M+ – CO2]), 117 (5), 115 (24), 90 (5), 84
Using 2d (117 mg, 0.5 mmol) gave 6a gave as a pale yellow solid
(70 mg, 50%); mp 66 °C; Rf = 0.26; [α]D25 –78 (c 1.0, CHCl3).
(37), 83 (20), 57 (65), 55 (100).
IR (ATR): 1824, 1662 cm–1.
Anal. Calcd for C10H16SO3: C, 55.53; H, 7.46. Found: C, 55.42; H,
7.35.
1H NMR (CDCl3): δ = 1.45 (s, 9 H, CH3), 3.15 (d, J = 6.0, 2 H,
CH2), 4.22 (d, J = 4.3 Hz, 1 H, CH), 4.99–5.07 (m, 1 H, CH), 7.15–
7.37 (m, 5 H, CH).
13C NMR (CDCl3): δ = 29.5, 39.0, 49.9, 67.0, 73.5, 127.4, 128.8,
129.2, 134.0, 162.6, 189.0.
(3S,4S)-3-(tert-Butoxycarbonyl)-4-methyloxetan-2-one (4c)
Using 2b (210 mg, 1.5 mmol) gave 4c as a colorless oil (166 mg,
60%); Rf = 0.35; [α]D25 –49 (c 1.0, CHCl3).
IR (ATR): 1823, 1725 cm–1.
MS: m/z (%) = 178 (12), 145 (100), 127 (38), 117 (37), 91 (34), 57
1H NMR (CDCl3): δ = 1.45 (s, 9 H, CH3), 1.56 (d, J = 6.2 Hz, 3 H,
CH3), 3.96 (d, J = 4.2 Hz, 1 H, CH), 4.85 (dq, J = 4.2, 6.2 Hz, 1 H,
CH).
(42).
HRMS: m/z [M + H]+ calcd for C15H19OS: 279.1055; found:
279.1059.
13C NMR (CDCl3): δ = 19.6, 27.8, 62.7, 71.2, 83.5, 162.9, 163.2.
(1R,5R)-6-(tert-Butoxycarbonyl)-3-oxa-6-azabicyclo[3.2.0]hep-
tane-2,7-dione (9)
MS: m/z (%) = 131 (3), 103 (11), 87 (23), 69 (76), 58 (100).
Analogously to the synthesis of compounds 3–6, β-lactam 9 (16 mg,
30%) was obtained as a colorless oil from 8a (X = NBoc, n = 1) (64
mg, 0.25 mmol); Rf = 0.23; [α]D26 +3.3 (c 1.0, CHCl3).
Anal. Calcd for C9H14O4: C, 58.05; H, 7.58. Found: C, 57.78; H,
7.56.
IR (ATR): 1815, 1764, 1723 cm–1.
(3S,4S)-3-[(tert-Butylsulfanyl)carbonyl]-4-methyloxetan-2-one
(4e)
1H NMR (CDCl3): δ = 1.54 (s, 9 H, CH3), 4.06 (d, J = 4.7 Hz, 1 H,
CH), 4.46 (dd, J = 4.8, 11.4 Hz, 1 H, CHaH), 4.71 (d, J = 11.4 Hz,
1 H, CHHb), 4.77 (dd, J = 4.8, 4.7 Hz, 1 H, CH).
13C NMR (CDCl3): δ = 28.0, 52.2, 54.6, 69.8, 85.3, 147.2, 155.5,
167.3.
MS: m/z (%) = 154 (21, [M+ – Ot-Bu]), 127 (1, [M+ – Boc]), 110
(3), 84 (22), 70 (15), 57 (100).
HRMS: m/z [2 M + Na]+ calcd for C20H26N2NaO10: 477.1486;
found: 477.1481.
Using 2b (210 mg, 1.5 mmol) gave 4e as a colorless oil (153 mg,
50%); Rf = 0.44; [α]D25 –45 (c 1.0, CHCl3).
IR (ATR): 1823, 1666 cm–1.
1H NMR (CDCl3): δ = 1.42 (s, 9 H, CH3), 1.54 (d, J = 6.2 Hz, 3 H,
CH3), 4.17 (d, J = 4.2 Hz, 1 H, CH), 4.89 (dq, J = 4.2, 6.2 Hz, 1 H,
CH).
13C NMR (CDCl3): δ = 19.5, 29.5, 49.8, 69.1, 70.8, 162.8, 189.1.
MS: m/z (%) = 158 (12, [M+ – CO2]), 102 (14), 69 (100), 57 (40).
Anal. Calcd for C9H14SO3: C, 53.44; H, 6.98. Found: C, 53.51; H,
7.02.
Acknowledgement
(3S,4S)-4-Methyl-3-[(propylsulfanyl)carbonyl]oxetan-2-one
(4f)
We thank the Deutsche Forschungsgemeinschaft for generous fi-
nancial support (grant Scho 402/9-2) and Dr. Holger Schmidt, Plant
Physiology, University Bayreuth, for HRMS spectra.
Using 2b (210 mg, 1.5 mmol) gave 4f as a colorless oil (142 mg,
50%); Rf = 0.38; [α]D25 –59 (c 1.0, CHCl3).
IR (ATR): 1823, 1669 cm–1.
1H NMR (CDCl3): δ = 0.93 (t, J = 7.3 Hz, 3 H, CH3), 1.58 (d,
J = 6.2 Hz, 3 H, CH3), 1.69 (qt, J = 7.2, 7.3 Hz, 2 H, CH2), 2.92 (t,
J = 7.2 Hz, 2 H, CH2), 4.27 (d, J = 4.3 Hz, 1 H, CH), 4.94 (dq,
J = 4.3, 6.2 Hz, 1 H, CH).
Supporting Information for this article is available online at
are experimental details and data for compounds 2–8.SnoIuiofpg
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13C NMR (CDCl3): 13.1, 19.6, 22.4, 31.3, 68.8, 71.0, 162.6, 189.1.
MS: m/z (%) = 144 (11, [M+ – CO2]), 69 (100).
References
(1) Yang, H. W.; Romo, D. Tetrahedron 1999, 55, 6403.
(2) Pommier, A.; Pons, J. M. Synthesis 1993, 441.
(3) Pommier, A.; Pons, J. M. Synthesis 1995, 729.
(4) Lowe, C.; Vederas, J. Org. Prep. Proced. Int. 1995, 27, 305.
(5) Böttcher, T.; Sieber, S. A. Angew. Chem. Int. Ed. 2008, 47,
4600.
(6) Tomoda, H.; Kumagai, H.; Tanaka, H.; Omura, S.
J. Antibiot. (Tokyo) 1993, 46, 872.
(7) Hadváry, P.; Sidler, W.; Meister, W.; Vetter, W.; Wolfer, H.
J. Biol. Chem. 1991, 266, 2021.
Anal. Calcd for C8H12SO3: C, 51.04; H, 6.43. Found: C, 51.32; H,
6.57.
(3S,4S)-3-[(tert-Butylsulfanyl)carbonyl]-4-isopropyloxetan-2-
one (5a)
Using 2c (252 mg, 1.5 mmol) gave 5a as a colorless oil (208 mg,
60%); Rf = 0.41; [α]D25 –50 (c 1.0, CHCl3).
IR (ATR): 1829, 1667 cm–1.
1H NMR (CDCl3): δ = 0.92 (d, J = 6.9 Hz, 3 H, CH3), 0.99 (d,
J = 6.6 Hz, 3 H, CH3), 1.43 (s, 9 H, CH3), 1.86–1.99 (m, 1 H, CH),
4.18 (d, J = 4.3 Hz, 1 H, CH), 4.40 (dd, J = 4.3, 8.2 Hz, 1 H, CH).
(8) Stork, G.; Szarjewski, R. P. J. Am. Chem. Soc. 1974, 437,
5787.
© Georg Thieme Verlag Stuttgart · New York
Synthesis 2013, 45, 773–776