[OH:1][C:2]([C:5]([CH3:11])([CH:9]=[CH2:10])[C:6]([OH:8])=[O:7])([CH3:4])[CH3:3].N1C(C)=CC=CC=1C.[C:20]([Si:24]([CH3:27])([CH3:26])Cl)([CH3:23])([CH3:22])[CH3:21]>ClCCl>[C:20]([Si:24]([CH3:27])([CH3:26])[O:1][C:2]([C:5]([CH3:11])([CH:9]=[CH2:10])[C:6]([OH:8])=[O:7])([CH3:4])[CH3:3])([CH3:23])([CH3:22])[CH3:21]A cooled (0° C.) solution of 2-(1-hydroxy-1-methyl-ethyl)-2-methyl-but-3-enoic acid (2.0 g, 12.6 mmol) and 2,6-lutidine (13.5 g, 126.4 mmol) in dichloromethane (150 mL) was treated with tert-butyldimethylchlorosilane (16.7 g, 63.2 mmol). After stirring for 1 h, the volatiles were removed in vacuo, the residue was taken in methanol (100 mL) and water (50 mL) and treated with potassium carbonate (20 g). After stirring for 16 h, the volatiles were removed in vacuo, the residue was diluted with water (50 mL), acidified to pH 2 with potassium hydrogen sulfate, and extracted with dichloromethane (3×25 mL). All the organics were combined and the volatiles were removed in vacuo to afford the title compound (3.288 g, 95%) as a clear oil. 1H NMR (300 MHz, CDCl3) δ 0.24 (s, 3H), 0.25 (s, 3H), 0.94 (s, 9H), 1.34 (s, 3H), 1.37 (s, 3H), 1.38 (s, 3H), 5.29 (m, 2H), 6.17 (dd, J=17.6, 10.9 Hz, 1H), 10.99 (br s, 1H).
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