Yield 51%.
M.p. 32–35 ºC (lit. 35–36 ºC; Ref. 5)
Rf 0.31 on SiO2 in 1:1 ethyl acetate:hexane
1H NMR (400 MHz, CDCl3) δ 2.67 (t, J = 6.9 Hz, 4H; C4, C6), 1.94 (p, J = 6.9 Hz, 2H; C5), 1.30 (s, 6H; CH3).
13C{1H} NMR (126 MHz, CDCl3) δ 210.5 (2C, C=O; C1, C3), 61.8 (1C, Cq; C2), 37.4 (2C, CH2; C4, C6), 22.3 (2C, CH3), 18.1 (1C, CH2; C5). Atom assignments are based on DEPT135 and HMBC analyses.
ESI-MS m/z calcd for [M+Na]+ 163.0730, found 163.0730.
IR (KBr, cm–1): ν(C–H) 2969, 2944, 2874; ν(C=O) 1728, 1697.