1858
Acknowledgements
Helpful discussions with Theodore Cohen and Michael Sponsler are gratefully acknowledged. A.R.H.
thanks the NSF for a CAREER Award.
References
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16. Adam, W.; Baeza, J.; Lin, J.-C. J. Am. Chem. Soc. 1972, 94, 2000–2006.
17. 2-Methyleneoxetanes 5 and 11 were prepared by the procedure described in Ref. 15a. All new compounds have been fully
characterized.
18. 3,3-Dimethyl-1-cyclohexyl-1-ol-4-phenyl-2-butanone (6b): 3,3-Dimethyl-4-phenyl-2-methyleneoxetane (5) (50 mg, 0.28
mmol) in dry THF (2 mL) was added to a cooled (−78°C) suspension under N2 of Li powder (30 mg, 4.30 mmol) and a
catalytic amount of DTTB (8.00 mg, 0.028 mmol) in dry THF (1 mL). The resulting deep green suspension was stirred for
2 h at rt. The reaction mixture was cooled (−78°C), and cyclohexanone (0.16 mL, 1.49 mmol) in THF (5 mL) was added
dropwise. The reaction mixture was stirred at −78°C for 1 h, followed by quenching with H2O (5 mL). The mixture was then
extracted with Et2O (3×10 mL). The organic layer was dried (MgSO4), and the solvent was removed in vacuo. Purification
by flash chromatography on silica gel (dry loaded CH2Cl2) (petroleum ether:EtOAc, 90:10) yielded a colorless oil (76 mg,
48%): IR (CHCl3): 3300, 2900, 1760, 780 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.08–7.28 (m, 5H), 2.81 (s, 2H), 2.58 (s,
2H), 1.21–1.73 (m, 10H), 1.12 (s, 6H); 13C NMR (100 MHz, CDCl3) δ 218.5, 137.4, 130.4, 128.0, 126.5, 70.5, 48.9, 47.3,
45.3, 37.5, 25.7, 24.2, 23.9, 21.8; anal. calcd for C18H26O2: C, 78.78; H, 9.56. Found: C, 78.52; H, 9.68.
19. For examples of tandem aldol–Tischenko reactions, see: Bodnar, P. M.; Shaw, J. T.; Woerpel, K. A. J. Org. Chem. 1997, 62,
5674–5675, and references cited therein.
20. Katritzky, A. R.; Wu, H.; Xie, L. J. Org. Chem. 1996, 61, 4035–4039.