Investigation of the three-dimensional structure of ?4-carene and its oxide

Lewis acid rearrangement of 2,3-epoxycarane. Formation of a novel m-menthenone

“…Forty minutes after initial oxide addition, the reaction mixture was cooled, taken up in 30 mL of ether, washed successively with water (2 X 10 mL), saturated NaHCOa (1 X 10 mL), and saturated NaCl (1 X 10 mL), and dried over anhydrous Na2S04. Partial removal of solvent under reduced pressure afforded an oily residue from which 2-methyl-4-isopropylcyclohex-3-en-l-one (9)15 was isolated by preparative VPC: IR (CCL,) 2975,1720,1360,1200,1180 (d), 970 and 930 cm"1; UV (95% EtOH) Xmax 290 nm ( = 90.9); NMR 6 1.04 (d, 6 H, J = 7 Hz, CH3CCH3), 1.14 (d, 3 H, J = 7 hz, CH3C-), 2.3 (quintet, 1 H, J = 7 Hz), 2.46 (n, m, 4 H), 2.88 (br q with additional splitting HCC=0), 5.37 (n, m, 1 H, HC=C); MS m/e (rel intensity) 153 (4), 152 (42), 135 (5), 100 (65), 109 (10), 96 (11), 95 (100), 81 (30), 68 (10), 67 (25), 55 (11). 2-Methyl-4-isopropylcyclohex-2-en-l-one (10).…”

“…(s,6 H, CH3CCH3), 1.27 (s, 3 H, CH3CO), 1.67 (t, 2 H superimposed on br m, 2 H, CH2CH2), 3.0 (d, 1 H, J = 2 Hz, HCO); MS m/e (rel intensity) 152(7),134 (73), 132 (19), 120 (20), 119 (100), 117 (34), 91 (67), 79 (15), 77 (23).…”