Noyori et al.
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Reaction of a,a'-Dibromo Ketones and Iron Carbonyls
SOC.,93, 4406 (1971). (28) C. A. Reed and W. R. Roper, J. Chem. Soc., Dalton Trans., 1365 (1973). (29) T. Yoshida, T. Okano, and S.Otsuka, J. Chem. SOC.,Dalton Trans., 993 (1976). (30) M. A. Bennett and T. Yoshida, J. Am. Chem. SOC.,95,3030 (1973). (31) R. J. Cross and F. Glockling, J. Chem. SOC.,5422 (1965). (32) R. J. D. Gee and H. M. Powell, J. Chem. SOC.A, 1956 (1971). (33) J. Chatt and B. T. Heaton, J. Chem. SOC.A, 2745 (1968). (34) M. A. Bennett, G. B. Robertson, P. 0. Whimp, and T. Yoshida, J. Am. Chem. SOC.,95, 3028 (1973). (35) T. G. Appleton and M. A. Bennett, J. Organornet. Chem., 55, C88 (1973); inorg. Chem., in press. (36) D. R . Coulson, J. Am. Chem. SOC.,98, 31 1 1 (1976). (37) H. D. Kaesz and R. B. Saillant, Chem. Rev., 72,231 (1972),and references cited therein. (38) K. Kudo, M. Hidai, and Y. Uchida. J. Organomet. Chem., 56, 413 (1973). (39) 8. L. Shaw and M. F. Uttley, J. Chem. SOC., Chem. Commun., 918 (1974). (40) M. Green, J. A. Howard, J. L. Spencer, and F. G. A. Stone, J. Chem. SOC., Chem. Commun., 3 (1975). (41) A. Immirzi, A. Musco, G. Carturan, and U. Belluco, lnorg. Chim. Acta, 12, L23 (1975). (42) T. Yoshida and S. Otsuka, J. Am. Chem. SOC.,99, 2134 (1977). (43) M. A. Bennett and D. L. Milner. J. Am. Chem. SOC.,91,6983 (1969). (44) G. W. Parshall, W. H. Knoth. and R. A. Schunn, J. Am. Chem. Soc., 91,4990 (1969). (45) A. Albert and E. P. Serjeant, "The Determinationof Ionization Constants", 2nd ed, Chapman and Hall, London, 1971, pp 86, 88. (46) K. Schorpp and W. Beck, Chem. Ber., 107, 1371 (1974). (47) J. Hillis, J. Francis, M. Ori. and M. Tsutsui, J. Am. Chem. SOC.,96, 4800 (1974). (48) J. R. Jones, "The Ionizationof Carbon Acids", Academic Press, New York, N.Y., 1973, pp 29, 64. (49) W. J. Bland, R. D. W. Kemmitt, and R. D. Moore, J. Chem. SOC., Dalton Trans.. 1292 (19731. (50) K.SuzukL H.'Yamamoto, and S. Kanie, J. Organomet. Chem., 73, 131 (1974). (51) R. Ros, J. Renaud, and R . Roulet. Helv. Chim. Acta, 58, 133 (1975). (52) W. Beck and M. Bauder, Chem. Ber., 103, 583 (1970). (53) A recent example is the formation of the Pt(PPh& complex of A'=CHCH3), 124; exact mass spectrum m/e 208.1844 (calcd for C14H240, 208.1826). 30 IR 1680 (C=O), 1655 cm-I (C=C); N M R 6 1.00 (s, CHC(CH3)3), 1.20 (s, =CC(CH3)3), 1.60-2.50 (m, CHC(CH3)3 and 2 CH2), 6.38 (m, =CH); mass spectrum m/e 208 (M+). Anal. (Cl4H240) C. H. Preparation of 2,6-Dibromo-2,6-diisopropylcyclohexanone (351. To a solution of 2,6-diisopropylcyclohexanone(465 mg, 2.55 mmol) in CH2C12 (3.0 mL) was added a solution of Br2 (920 mg, 5.75 mmol) in the same solvent (3.0 mL) with stirring a t 25 "C over a period of 15 min and the stirring was continued for an additional 30 min. The resulting mixture was diluted with CH2Cl2 ( I O mL) and washed with water (3 mL). The organic layer was dried over MgS04 and concentrated to afford an oily material ( 1 g). The residue was subjected to bulb-to-bulb distillation, giving 35 (bp 130-140 OC (bath temperature), 0.05 mm, 708 mg, 82% yield) as a pale yellow liquid: IR 1720 cm-' (C=O);NMR60.98and 1.16 ( t w o d , J = 7.0 Hz,CH(CH&), 1.5-3.0 (m,3 CH2 and 2 CH); mass spectrum m/e 342,340,338 (1 :2:1 ratio, M+). Anal. (C12HzoOBr2) C , H. Reaction of 35 and Fez(C0)9in Methanol. A mixture of Fe2(CO)9 (437 mg, I .20 mmol) and 35 (340 mg, 1 .OO mmol) in dry, degassed methanol (8.0 mL) was left with stirring at 25 "C for 24 h under argon. The reaction mixture was evaporated under reduced pressure and the residue was treated with saturated ethylenediaminetetraacetic acid disodium salt (Nazedta) solution. The aqueous layer was extracted with CH2C12 (10 mL X 2). The combined organic extracts were washed with water, dried over Na2S04, and concentrated, leaving a pale green oil (208 mg). Preparative T L C (benzene) produced trans-2,6-diisopropyl-2-methoxycyclohexanone(37) ( R f 0.20, 40 mg, 19% yield) and a 2:l mixture of cis-37 (42% yield) and 2,6diisopropylcyclohex-2-enone(36) (21% yield) (Rf 0.43-0.63, 126 mg). Analytical samples of cis-37 and 36 were obtained by repeated chromatography (1 :40 ether-hexane, Rf 0.4 and 0.5, respectively). 3 6 I R (neat film) 1675 (C=O), 1640 cm-l (C=C); N M R 6 0.85 and 0.92 (two d, J = 7.0 Hz, CHCH(CH3)2), 0.98 (d, J = 7.0 Hz,
1764
Journal of the American Chemical Society
CCH(CH&), 1.60-2.55 (m, 2 CH2 and CHCH(CH3)2), 2.75 (seven-line m, J = 7.0 Hz, = C C H ) , 6.49 (t, J = 4.5 Hz, =CH);exact mass spectrum m/e 180.1510 (calcd for C12H200. 180.1514). cis-37: IR 1744, 1714 cm-l (C=O); N M R 8 0.65-0.95 (complex m, 2 CH(CH&), 1.20-3.00 (m, 3 CH2 and 2 CH), 2.97 (s, OCH3); exact mass spectrum m/e 212.1796 (calcd for Cl3H2402, 212.1776). trans-37: IR 1720 cm-I (C=O); N M R 6 0.61-0.97 (complex m,2 CH(CH&), 1.20-2.95 (m, 3 CH2 and 2 CH), 3.18 (s, OCH3); exact mass spectrum m/e 212.1783 (calcd for C13H2402, 212.1776). Reaction of 2,4-Dibromo-2,4-dimethylpentan-3-one(38) with Fez(C0)gin the Presence of Sodium Acetate. A mixture of Fe2(C0)9 (437 mg, 1.20 mmol), 38 (272 mg, 1.OO mmol), and anhydrous sodium acetate (200 mg, 2.47 mmol) in dry D M F (2.5 mL) was stirred at 30 "C for 19 h under N2 and quenched by water ( I O mL). The aqueous layer was extracted with 1:l ethyl acetate-hexane. The combined organic solutions were washed with water and dried over Na2S04. The GLC analysis (column E, 60 "C) of the organic layer showed that two products were formed. One of them was assigned to 2,4-dimethylpent-I-en-3-one (41)(20% yield based on GLC using 2-methylpentan-3-one as an internal standard) by comparison of the GLC retention time with that of an authentic sarnple.l0 2-Acetoxy-2,4-dimethylpentan-3-one (40,88 mg, 60% yield) was isolated by evaporation of the solvent followed by preparative TLC (1:lO ethyl acetate-hexane, Rf0.6). Its IR and N M R spectra were in accord with those reported in the 1 i t e r a t ~ r e . l ~ Reaction of 38 with Fez(C0)g in DMF. A mixture of 38 (833 mg, 3.06 mmol) and Fe2(C0)9 (1.31 g, 3.60 mmol) in D M F (10.5 mL) was stirred at 25 "C for 18 h under N2. Octane was added to the reaction mixture as internal standard. GLC analysis (column E, 90 "C) indicated that 41 and 2,4-dimethylpentan-3-onewere formed in 80 and 9% yields, respectively. Reaction of 2,4-Dibromo-2-methylpentan-3-one (42)with FeZ(C0k in Methanol. A mixture of 42 (774 mg, 3.00 mmol) and Fe2(C0)9 (1.3 1 g, 3.60 mmol) in dry, degassed methanol (6.0 mL) was stirred at 25 "C for 38 h under argon. The mixture was quenched by the addition of saturated NaHCO3 solution ( I O mL) and extracted with CHzC12 ( I O mL X 3). GLC analysis (column E, 50 "C) of the extract (48).The comshowed the absence of 2,4-dimethylpent-l-en-3-one bined organic extracts were dried over Na2S04. The solvent was removed by distillation through a 30-cm Vigreux column under ordinary pressure, leaving a yellow oil (500 mg). To the residue was added a small amount of CH2C12 and the precipitated insoluble materials were filtered off. The filtrate was distilled with a bulb-to-bulb system, affording a 90:lO mixture (determined by N M R analysis) of 2-methoxy-2-methylpentan-3-one(44) and 2-methoxy-4-methylpentan3-one (45) (bp 70-80 "C (bath temperature), 100 mm, 177 mg, 45% combined yield). The spectral properties (IR, N M R , and mass spectra) and chromatographic (GLC and TLC) behavior were quite identical with those of authentic samples prepared by the reported
procedure^.^'^^^ Reaction of 42 with Fez(C0)g in the Presence of Sodium Acetate in DMF. A mixture of 42 (258 mg, 1.OO mmol), Fez(C0)9 (437 mg, 1.20 mmol), and anhydrous sodium acetate (410 mg, 5.00 mmol) in DMF (2.0 mL) was stirred at 25 "C for 16 h under argon. To this was added saturated Nazedta solution (10 mL) and the mixture was extracted with 1:l ethyl acetate-hexane ( I O mL X 3). The combined extracts were dried over Na2S04. GLC analysis (column E, 50 "C, methyl isopropyl ketone as internal standard) of the organic layer indicated the occurrence of a small amount (
