We previously reported the isolation and the characterization of new constituents from Japanese hop "Shinshu-wase" (l)(2). The present paper deals with the investigation of new monoterpene ethers and ketone from the ssme source, namely hop ether (I), karahana ether (V) and karahanaenone (IX).
By silica gel column chromatography of the fraction, boiling at 50-53O/15 mm Hg, hop ether and karahana ether were eluted successively. Hop ether (I), CloH160, has following physical properties. vmax 3070, 1650, 880 cm-l (terminal methylene), 1380, 1361 cm-' (gem-dimethyl), 1145, 1125, 1050 cm -1 (cyclic ether). $::4 1.14 and 1.18 (each 3H, s., (CH3)2&0-), 1.50-1.80 (2H, m., -CH2-), 2.15-2.60 (35, m., -bH-and =b-CH2-), ca. 3.2 (lH, m., =&-&I-), 3.53 (IH, d.d., J=8.2, 4.5 cps) and 4.00 (lH, d.d., J=8.2, 8.2 cps) (-CH,-0-), 4.72 and 4.85 (each lH, slightly split signals, =CH2). m/e 152 (M+), 122 (M-3C), 107 (M-30-15), 94 (M-58), 79 (base peak). Hydrogenation of I in ethanol with platinum oxide yielded the dihydro hop ether, C10H180 (II). In the NMR spectrum of II, in addition to gem-dimethyl signals at 1.10 and 1.12 ppn, a doublet (J=6.7 cps) was observed at 0.97 ppm instead of the terminal methylene signals of I. Signals of ordinary methine and methylene protons (7H) and a doublet at 3.58 ppm (2H, J=6.7 cps, -CH2-0-) were also observed. In the MS spectrum of II, besides M+ ion (m/e 154) and base peak (m/e 43). the following ions are remarkable, m/e 139 (M-15), 96 (M-58) and (M-58-15). In the comparison of the MS spectra of I and II, the ions, M-58, were observed in the both, whereas a pair of characteristic peaks in the former, M-30 and M-30-15, was negligible in the latter. On the basis of the above spectral data (IR, NMR and MS spectra), hop ether must have the partial structure of