Reaction Steps
A solution of geraniol (225 ul, 1.29 mmol, 1.0 equivalent) and triethylamine (271 ul, 1.94 mmol, 1.5 equivalent) in dry dichloromethane (I ml) was cooled to −78 C and treated dropwise with 3,3-dimethylacryloyl chloride (159 ul, 1.43 mmol, 1.1 equivalent). After 3 h, the solution was diluted with water (1 ml) and dichloromethane (1 ml), and the cooling hath was removed. The mixture was extracted with dichloromethane (3×20 ml), and the combined organics were dried (MgSO4) and concentrated in vacuo. Purification by radial chromatography (4 mm SiO2 plate; elute, 7% EatOAc-hexanes; product, fractions 4-6; 30 ml/fraction) afforded ##STR3## (301 mg, 1.27 mmol, 99% yield) as a clear oil: Rf starting material, 0.14; product, 0.51 (5:1 hexanes-EtOAc, anisaldehyde); FTIR (film) 2970, 2919, 2858, 1738, 1653, 1445, 1377, 1206, 1153, 987, 896 cm-1; sup. 1H NMR (400 MHz, CDCl3) δ 5.31-5.35 (m, 1H), 5.04-5.08 (m, 1H), 4.88 (bs, 1H), 4.83 (bs, 1H), 4.60 (s, 1H), 4.58 (s, 1H), 3.01 (s, 2H), 2.00-2.09 (m, 4H), 1.79 (s, 3H), 1.69 (s, 3H), 1.66 (s, 3H), 3.01 (s, 2H), 2.00-2.09 (m, 4H), 1.79 (s, 3H), 1.69 (s, 3H), 1.66 (s, 3H), 1.58 (s, 3H); .sup.13 C NMR (101 Mhz, CDCl3) δ 171.2, 142.2, 138.6, 131.7, 123.7, 118.2, 114.5, 61.4, 43.4, 39.4, 26.2, 25.6, 22.3, 17.6, 16.4; HRMS (EI, Pos) m/z calculated for [C15H24O2]+236.1776, found 236.1768.
