Synlett 2008(18): 2763-2768  
DOI: 10.1055/s-0028-1083549
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

A Short and Efficient Synthesis of 3-Spiro-α-methylene-γ-butyrolactone Oxindolones from Isomerised Bromo Derivatives of Morita-Baylis-Hillman Adducts

Ponnusamy Shanmugam*, Baby Viswambharan
Chemical Sciences and Technology Division, National Institute for Interdisciplinary Science and Technology (NIIST), Thiruvananthapuram 695 019, Kerala, India
Fax: +91(471)2491712; e-Mail: shanmu196@rediffmail.com;
Further Information

Publication History

Received 2 June 2008
Publication Date:
16 October 2008 (online)

Abstract

A short and efficient synthesis of α-methylene-γ-butyrolactone-3-spirooxindolones by the reaction of isomerised bromo derivatives of Morita-Baylis-Hillman adducts of isatin and formaldehyde followed by acid-catalysed lactonisation has been achieved. The oxindolidino allyl bromide has been used for the first time for the allylation of aldehydes to afford a 2-oxindolidino homoallylic alcohol which on acid-catalysed lactonisation delivered the title compounds in excellent yield. Synthetic transformation of the spirolactone oxindole is demonstrated with the preparation of an oxirane derivative and a second Morita-Baylis-Hillman adduct.

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Typical Procedure: A mixture of isomerised MBH adduct (100 mg), 40% aq formaldehyde (1.2 equiv) and indium powder (1.6 equiv) in DMF (1 mL) was stirred at r.t. for 6 h. After completion (TLC), the reaction was quenched with sat. NH4Cl and stirred further for half an hour. The resulting crude homoallylic alcohol was extracted with EtOAc, dried and concentrated. The crude homoallylic alcohol compound in benzene (1 mL) was subjected to lactonisation with PTSA (0.2 equiv) under reflux for 30 min. After the completion of the reaction (TLC), PTSA was removed by washing with H2O. The organic layer was washed with brine, evaporated in vacuo and then purified by silica gel column chromatog-raphy to afford the products (65-85%).
Spectral Data for Selected Compounds: Compound 4: FTIR (CH2Cl2): 1613, 1715, 3004 cm. ¹H NMR (300 MHz, CDCl3/TMS): δ = 2.65 (s, 3 H), 3.20 (s, 3 H), 3.90 (s, 3 H), 6.79-6.81 (d, 1 H, J = 7.8 Hz), 6.95-7.00 (d, 1 H, J = 7.8 Hz), 7.26-7.31 (d, 2 H, J = 7.8 Hz). MS (FAB): m/z calcd for C13H13NO3: 231.24; found [M + 1]: 232.38. Compound 5: FTIR (CH2Cl2): 1613, 1715, 2995 cm. ¹H NMR (300 MHz, CDCl3/TMS): δ = 2.44 (s, 3 H), 3.23 (s, 3 H), 3.96 (s, 3 H), 6.81-6.84 (d, 1 H, J = 7.8 Hz), 7.03-7.08 (d, 1 H, J = 7.8 Hz), 7.29-7.34 (d, 1 H, J = 7.8 Hz), 7.51-7.54 (d, 1 H, J = 7.8 Hz). MS (FAB): m/z calcd for C13H13NO3: 231.24; found [M + 1]: 232.35. Compound 6: FTIR (CH2Cl2): 1115, 1613, 1715, 2920, 3265 cm. ¹H NMR (300 MHz, CDCl3/TMS): δ = 1.70 (br s, 1 H), 3.30 (s, 3 H), 3.50 (s, 3 H), 3.78-3.81 (d,
1 H, J = 11.4 Hz), 4.13-4.17 (d, 1 H, J = 11.4 Hz), 6.26 (s,
1 H), 6.64 (s, 1 H), 6.88-6.91 (m, 1 H), 7.00-7.05 (m, 2 H), 7.20-7.30 (m, 1 H). MS (FAB): m/z calcd for C14H15NO4: 261.27; found [M + 1]: 262. 38. Compound 7: FTIR (CH2Cl2): 1115, 1613, 1715, 1766, 2920 cm. ¹H NMR (300 MHz, CDCl3/TMS): δ =3.26 (s, 3 H), 4.41-4.44 (d, 1 H, J = 9.3 Hz), 4.68-4.71 (d, 1 H, J = 9.3 Hz), 5.35 (s, 1 H), 6.31 (s, 1 H), 6.91-6.94 (d, 1 H, J = 6.0 Hz), 7.11-7.21 (m, 2 H), 7.36-7.40 (d, 1 H, J = 6.0 Hz). ¹³C NMR (75 MHz, CDCl3/TMS): δ = 27.1, 54.5, 73.0, 108.2, 109.2, 109.5, 122.5, 123.2, 130.3, 137.5, 143.8, 168.47, 175.5. MS (FAB): m/z calcd for C13H11NO3: 229.23; found [M + 1]: 230.3. Compound 18: FTIR (CH2Cl2): 1116, 1618, 1720, 1770, 3020 cm. ¹H NMR (300 MHz, CDCl3/TMS): δ = 2.34 (s,
3 H), 3.20 (s, 3 H), 4.40-4.43 (d, 1 H, J = 9.0 Hz), 4.67-4.70 (d, 1 H, J = 9.0 Hz), 5.36 (s, 1 H), 6.36 (s, 1 H), 6.80-6.82 (d, 1 H, J = 6.0 Hz), 7.01 (s, 1 H), 7.18-7.16 (d, 1 H, J = 6.0 Hz). ¹³C NMR (75 MHz, CDCl3/TMS): δ = 20.9, 26.7, 54.3, 72.6, 109.1, 123.7, 124.4, 129.8, 130.6, 133.5, 137.4, 141.0, 168.32, 175.2. MS (FAB): m/z calcd for C14H13NO3: 243.25; found [M + 1]: 244.3. Compound 19: FTIR (CH2Cl2): 1114, 1347, 1610, 1688, 1731, 1770, 2925 cm. ¹H NMR (300 MHz, CDCl3/TMS): δ = 3.32 (s, 3 H), 4.45-4.48 (d, 1 H, J = 9.0 Hz), 4.69-4.72 (d, 1 H, J = 9.0 Hz), 5.36 (s, 1 H), 6.41 (s, 1 H), 7.07-7.09 (d, 1 H, J = 6.0 Hz), 7.75 (s, 1 H), 7.92-7.94 (d, 1 H, J = 6.0 Hz), 9.91 (s, 1 H). ¹³C NMR (75 MHz, CDCl3/TMS): δ = 27.1, 53.9, 72.1, 105.4, 123.6, 125.0, 130.9, 132.74, 133.7, 136.6, 148.9, 167.6, 175.4, 190.1. MS (FAB): m/z calcd for C14H11NO4: 257.24; found [M + 1]: 258.6. Compound 24: FTIR (CH2Cl2): 1613, 1715, 1750, 3004 cm. ¹H NMR (300 MHz, CDCl3/TMS): δ = 3.20 (s,
3 H), 3.37-3.41 (d, 1 H, J = 12.0 Hz), 3.81-3.85 (d, 1 H, J = 12.0 Hz), 4.25-4.28 (d, 1 H, J = 9.0 Hz), 4.78-4.82 (d, 1 H, J = 9.0 Hz), 6.99-7.02 (d, 1 H, J = 9.0 Hz), 7.14-7.26 (m,
2 H), 7.42-7.47 (t, 1 H, J = 9.0 Hz). MS (FAB): m/z calcd for C13H11NO4: 245.24; found [M + 1]: 246.38. Compound 25: FTIR (CH2Cl2): 1613, 1715, 1750, 3004, 3282 cm. ¹H NMR (300 MHz, CDCl3/TMS): δ = 1.68 (s, 1 H), 3.32 (s,
3 H), 4.45-4.48 (d, 1 H, J = 9.0 Hz), 4.69-4.72 (d, 1 H, J = 9.0 Hz), 5.36 (s, 1 H), 5.58 (s, 1 H), 5.63 (s, 1 H), 6.41 (s,
1 H), 7.06-7.09 (d, 1 H, J = 6.0 Hz), 7.75 (s, 1 H), 7.91-7.96 (d, 1 H, J = 6.0 Hz). MS (FAB): m/z calcd for C17H14N2O4: 310.30; found [M + 1]: 311.41.