Mitsuko Kikuchi

Lanthanide- and aromatic solvent-induced shift effects on proton resonances in C-4-methylated steroids and tetracyclic triterpenoids

Abstract Lanthanide-induced shifts (LIS) with Eu (dpm)3 and aromatic solvent induced shifts (ASIS) with C4H4, C5H5N1 and C6F6 of PMR signals were examined for a series of C-4-methylated steroids and tetracyclic triterpenoids having a hydroxyl, carbonyl or acetoxyl group at position C-3. The magnitude and/or direction of the LIS (or ASIS) of corresponding protons were extensively influenced by the nature of the C-3-functional groups. The possible geometries of Eu (dpm)3-substrate complexes were also discussed on the basis of the LIS data. The above two techniques in the PMR spectroscopy provided the confirmatory evidence for the structural and stereochemical determination of steroids and triterpenoids.

Synthesis of Optically Active Whisky Lactone

SUMMARY The cis -and trans -5-butyltetrahydro-4-methylfuran-2-ones(=whisky or quercus lactones) have been identified as aroma components of aged alcoholic beverages such as whisky, brandy, and wine. The optically active cis -whisky lactone have been prepared from (S)-(-)-1-(1,3-dithian-2-yl)-1-pentanol, which was obtained by the bakers yeast reduction of 1-(1,3-dithian-2-yl)-1-pentanone. And key step lactonization employed intramolecular Wittig reaction.

Steam Volatile Constituents From Seeds of Momordica Charantia L

ABSTRACT Steam distillates from seed oils and seeds, except for the crusts (embryos), of Momordica charantia L. (Japanese name: Nagareishi and Futoreishi) under reduced pressure (250-310 mmHg) by using a cold trap connected to a receiver and by the SDE method, were extracted with a mixed solvent (C 5 H 12 -Et 2 0, 2:1). In the case of steam distillates from seed oils, seven acidic compounds, nineteen n -paraffins (C 12 -C 20 ), a compound C 10 H 16 0 (M + 152) with a unique fragrance, p -cymene, l -menthol, nerolidol, pentadecanol, hexadecanol and squalene were identified. In the case of seeds, except for the crusts (embryos), nine aldehydes (mainly pentanal, trans -2-hexenal, t -2-heptenal and 2( E ), 4( E )-nonadienal), six alcohols, four acids (mainly valeric acid), four esters (mainly amyl formate and amylvalerate), four acetals, 2-butylfuran and 2-hexanone were identified.