CHARACTERIZATION OF TRIMETHPLSILYLCYCLOHEXANOLS2483 exo-7-Acetoxy 1,6-dimethylbicyclo [4.1 .O]heptane.'8--To a solution of 5.0 g (29.8 mmoles) of exo acid, mp 137-139', in 100mlof anhydrous ether, was added with stirring 160 ml of a solution of methyllithium in ether containing 59.6 mmoles of total base as l?termined by titration. After 5 min the reaction mixture was worked up, yielding 1.75 g of recovered starting material, mp 136-139", and 3.34 g of neutral product. The small amount of less volatile tertiary alcohol (2.87 p ) cont,aminating the product was removed by distillation through a spinning-band column at oil pump pressure which gavc 2.08 g of ketone (65% based on unrecovered acid): bp 29-30' (0.2 mm); 5.92 p ;210 mp ( E 6800); I (CC1.t) 7.89 (3 H) and 8.80 (6 H).To a slurry of 2.00 g (12.0 mmoles) of ketone and t 6 g of dibasic sodium phosphate in 80 ml of methylene chloride was added, with stirring, a solut,ion of peroxytrifluoroacetic acid prepared by adding, with stirring, 1.0 ml (37 mmoles) of 90% hydrogen peroxide and 6.2 ml (44 mmoles) of trifluoroacetic anhydride to 15 ml of ice-cooled methylene chloride. Work-up gave 1.50 g of crude product which was first subjected to shortpath dist,illation (oil bath 105-140") and then preparative gc. Material corresponding to the major peak (85%) at 6.7 rnin was collected: A tz 5.73 p ; I (CClr) 6.42 (1 H) 8.00 (3 H), 9.03 ( 6 H). A n d . Calcd for CI1HlnO2: C, 72.53; H, 9.89. Found: C, 72.76; H, 10.07.Conversion of the cyclopropyl acetate to cyclopropanol was effected by using freshly dist,illed solvents for each run (including work lip). Typically, a solution of 37 mg of acetate in a mixture of 2.5 ml of methanol and 1.5 ml of 0.3 N sodium hydroxide sohition was allowed to st and at room temperature for 50 miri under nitrogen. Water (10 ml) was then added and the mixture was extracted with three 3-ml portions of pentane. The combined extracts were washed with 2 ml of water and then dried over sodinm snlfate. Evaporation of solvent left a white solid showing hydroxylir (2.8 and 2.9 p ) but no carbonyl absorp tion; 7 (CDCI,) 6.93 (1 H), 8.07 ( 1 H), 8.95 (1 HI singlet superimposed on complex absorption).The white solid from one run was treated with excess acetic anhydride in pyridine. Work-up, nsing carbon tetrachloride as solvent, gave a solution showing the same nmr absorption as (18) General procsedures: G. Tegner, Acta Chem. S c a d . , 6, 782 (1952); K, D. Emmons and G. 13. Lneas, J. Am. Chem. Sac., 77, 2287 (1955); C. H. DePuy and L. R. Slahoney, {bid., 86, 2653 (1964).starting acetate. Capillary gc of the concentrated solution showed, apart from solvent, only one peak with a retention time corresponding to that of starting acet,ate. endo-7-Acetoxy-l,6-dimethylbicyclo[4.1 .O] heptane was similarly prepared18 from endo acid, mp 120-122"; 1.450 g of the acid yielding 0.800 g of crude ketone which showed only weak hydroxyl absorption in the infrared spectrum. A portion (580 mg) of this crude ketone was subjected to Baeyer-Villiger oxidation, giving 549 mg...
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