Triethylamine → [(6-tert-Butyldimethylsilyloxy-2-naphthyl)methoxymethylene]adamantane

Participants

Reaction Steps

A 250 mL three-neck flask was fitted with a reflux condenser. 125 mL addition funnel, CaCl2 drying tube and nitrogen line. The apparatus was dried by means of a hot air gun and nitrogen purging. THF (150 mL) distilled from Na/benzophenone was added and the flask cooled in an ice-water bath. Titanium trichloride (12 g, 78 mmol) was added rapidly (fumes in air|) followed by lithium aluminum hydride (1.425 g, 37.5 mmol) in portions with vigorous stirring. The cooling bath was removed and the black mixture was allowed to warm to room temperature. Triethylamine (6 mL, 43 mmol) was added dropwise to the stirred suspension and reflux begun. After 1 hour at reflux, a solution of methyl 6-tert-butyldimethylsilyloxy-2-naphthoate (2.38 g, 7.5 mmol) and adamantanone (1.15 g, 7.67 mmol) in 50 mL of dry THF was added dropwise to the refluxing mixture over an 18 hour period. Reflux was continued for an additional 6 hours. The cooled reaction mixture was quenched by careful addition of 10 mL of methanol and 10 mL of water. The mixture was diluted with 50 mL of pentance and passed down a column of florisil (4"×1.5"), eluting with pentane, then 1:1 ether/pentane. If any of the black material passes through the column it may be removed by extracting the organic phase with water. The pooled organic solutions were concentrated on a rotary evaporator producing a yellow oil which was chromatographed on silica with 5% (V/V) ethyl acetate/hexane. The product containing fractions when evaporated left 1.8 g of a yellow oil which afforded 1.27 g of 1c as slightly yellow crystals from cold pentane: mp 97.5°-98° C.; 1H NMR delta 0.250 (s, 6H), 1.024 (s, 9H), 1.80-1.99 (m, 13H), 2.697 (s, 1H), 3.321 (s, 3H), 7.05-7.72 (m, 6H); 13C NMR delta -4.34, 18.27, 25.73, 28.39, 30.28, 32.32, 37.25, 39.13, 39.28, 57.76, 114.78, 122.19, 126.32, 127.74, 128,06, 128.86, 129.44, 130.88, 131.56, 134.00, 143.73, 153.70; MS m/e (rel. intensity) 435 (37, M+1), 434 (100), 377 (18), 345 (5), 188 (6), 162 (18), 14 (11), 73 (20). IR (KBr) 2940, 2915, 1630, 1600, 1480, 1265, 1250, 1090, 855, 840 cm-1. ##STR30##

Provenance & Evidence