• Applied Biological Chemistry
• /
• 제31권3호
• /
• pp.292-297
• /
• 1988

토마토 과실의 향기성분을 생체흡착법, 파쇄흡착법 및 연속 수증기증류법으로 추출하고 GC와 GC-MS에 의해 동정하였다. 생체흡착법으로 추출한 향기성분은 80여 종 이상이 분리되었고 그 중 alcohols 10종, aldehydes 6종, ester 3종, ketones 4종, phenol 1종, acid 1종으로 총 25종을 동정하였다. 파쇄흡착법으로 추출한 향기성분은 100여종 이상이 분리되었고 그중 alcohols 12종, aldehydes 6종, Ketones 5종, esters 5종, phenols 2종, hydrocarbon 1종, acid 1종으로 총 32종이 동정되었다. 연속수증기증류법으로는 향기성분 300여종 이상을 분리하였고 그 중 alcohols 19종, ester 9종, hydrocarbons 13종, aldehydes 8종, Ketones 9종, phenols 2종, lactones 2종, furans 2종, acid 1종, oters 2종으로 총 67종이 동정되었다. 연속수증기 증류법에 의해 동정한 성분 중 아직까지 MS에 의해 동정되지 않은 성분들은 hydrocarbons 11종, aldehydes, Ketones 및 other 각각 2종, alcohol, ester, lacton 및 furfural 각각 1종으로 총 21종이었다.

• Bulletin of the Korean Chemical Society
• /
• 제17권10호
• /
• pp.900-905
• /
• 1996

Details are described of reaction of carbonyl compounds with diisobutyldialkylaminoalane (DIBAL-NR2; R=Et, i-Bu, Ph) in order to establish their reduction characteristics. The reagents were extremely mild and reduced only aldehydes and ketones effectively in ethyl ether at 25 ℃. The stereoselectivity in the reduction of representative cyclic ketones appeared not so high but quite different from that obtained by DIBAL-H itself. The reagents reduced α,β-unsaturated aldehydes and ketones to the corresponding allylic alcohols without any detectable 1,4-reduction products. DIBAL-NR2 also achieved the selective reduction of aldehydes or ketones in the presence of keto or other readily reducible functional group, however the chemoselectivity was less satisfactory than that achieved by diisobutylethoxyalane (DI-BAL-OEt).

• Bulletin of the Korean Chemical Society
• /
• 제19권2호
• /
• pp.236-242
• /
• 1998

Reaction of carbonyl compounds with Al-alkoxydiisobutylalane (DIBAOR, R=H, Et, i-Pr, t-Bu) has been investigated in detail so as to establish their usefulness as selective reducing agents in organic synthesis. The reagents appear to be extremely mild and can reduce only aldehydes and ketones effectively under mild conditions. All the other common organic functional groups are not affected by these reagents. The reagents can also reduce α,β-unsaturated aldehydes and ketones to the corresponding allylic alcohols without any detectable 1,4-reduction. Furthermore, the reagents show a highly chemoselective discrimination between aldehyde and ketone, between aldehydes, and between ketones. Even more remarkable is the stereoselective reduction of cyclic ketones to the thermodynamically more stable alcohol epimers.

• Bulletin of the Korean Chemical Society
• /
• 제5권6호
• /
• pp.240-244
• /
• 1984

8-Oxyquinoline dihydroboronite is prepared by mixing equimolar amounts of 8-hydroxyquinoline and borane-dimethyl sulfide complex in tetrahydrofuran at room temperature and its structure is determined by spectroscopic methods. The reagent is shown to be an extremely mild reducing agent and reduces aldehydes, cyclohexanones, and acid chlorides to some extent. The reagent in the presence of 0.1 equiv of boron trifluoride etherate in tetrahydrofuran at room temperature reduces selectively aldehydes in the presence of ketones, while the reagent in the presence of 1 equiv of boron trifluoride etherate rapidly reduces simple aldehydes and ketones but does not reduce carboxylic acids, esters, and amides.

• Bulletin of the Korean Chemical Society
• /
• 제17권1호
• /
• pp.50-55
• /
• 1996

Reaction of carbonyl compounds with diisopinocampheylhaloboranes (Ipc2BX,X=Cl, Br, I) was investigated in detail in order to establish their usefulness as selective reducing agents. The reagents reduced aldehydes and ketones to the corresponding alcohols. The reactivities are in the order of Ipc2BCl Ipc2BBr>Ipc2BI.The reagents also reduced ${\alpha}{\beta}-unsaturated$, aldehydes and ketones to the corresponding allylic alcohols without any detectable 1,4-reduction. Especially, the chloro derivative nicely achieved the selective reduction of aldehyde or ketone groups in the presence of many other functional groups. The most remarkable result of this investigation is that aldehydes and ketones can be selectively reduced in the presence of acid chlorides.

• 한국식품영양학회지
• /
• 제30권1호
• /
• pp.120-128
• /
• 2017

This study aimed to provide volatile flavor compounds of three onion products through thermal process and alcohol fermentation, to meet the quality standard of onion products. The identified components of onion extracts (OE) included 49 (18 sulfur-containing compounds, 5 alcohols, 8 acids, 3 ketones, 4 esters, 4 aromatic compounds, 2 aldehydes, 1 pyrazines and 4 miscellaneous compounds), and 55 (17 sulfur-containing compounds, 15 alcohols, 5 acids, 11 ketones, 3 aromatic compounds, 2 aldehydes and 1 pyrazine) in autoclave-sterilized onion extracts (SOE); and 69 (10 sulfur-containing compounds, 27 alcohols, 11 acids, 11 ketones, 6 esters, 1 aromatic compound and 3 pyrazines) in onion wine (OW), respectively. Among the major flavor classes, sulfur-containing compounds (36.8%), acids (31.3%) and aldehydes (13.6%) in OE were changed to alcohols (46.5%) and ketones (27.3%) in SOE whereas, alcohols (56.3%) and acids (26.6%) in OW. Moreover, 1,3-butanediol, 2,3-butanediol, and 3-hydroxy-2-butanone were highly detected in SOE whereas, acetic acid, 3-methylbutanol, 2-phenylethanol and 1,2,3-propanetriol in OW.

• Bulletin of the Korean Chemical Society
• /
• 제26권12호
• /
• pp.1962-1964
• /
• 2005

Zirconium(IV) chloride is found to be an efficient catalyst for the electrophilic addition reaction of indole with aldehydes/ketones to afford the corresponding bis(indolyl methanes in good yields. The remarkable features of this new procedure are high conversions, shorter reaction times, cleaner reaction profiles and simple experimental and work-up procedures.

• Bulletin of the Korean Chemical Society
• /
• 제29권1호
• /
• pp.76-80
• /
• 2008

Reductive acetylation of a variety of carbonyl compounds such as aldehydes, ketones and a,b-unsaturated enals/enones was carried out efficiently with pyridine zinc borohydride, (Py)Zn(BH4)2, in a mixture of THF-EtOAc at room temperature or under reflux condition. The corresponding acetates were obtained in high to excellent yields. In addition, chemoselective reductive acetylation of aldehydes over ketones was achieved perfectly with the reagent at room temperature.

• 한국식품영양과학회지
• /
• 제24권3호
• /
• pp.420-426
• /
• 1995

Volatile compounds in raw oyster and oyster hydrolysate produced with protease were compared by vacuum simultaneous steam distillation-solvent extraction/gas chromatography/mass spectrometry. Sixty-two volatile compounds were detected in both samples. Of these, 57 were positively identified, composed mainly of aldehydes(12), ketones(9), alcohols(14), nitrogen-containing compounds(9), acids(6), terpenes(4), and miscellneous compounds(8). Levels of acids decreased after hydrolysis, whereas several other compounds such as aldehydes, ketones, and nitrogen containing compounds increased. Pyrazines, found in high abundance, were only detected in oyster hydrolysate.

• Bulletin of the Korean Chemical Society
• /
• 제16권4호
• /
• pp.349-355
• /
• 1995

Bromo-and chlorotrimethylsilane react with selenium dioxide in halocarbon solvents and generate selenium oxybromide and oxychloride, respectively. These in-situ generated oxyhalides turned out to be very efficient for selective bromination and chlorination of aldehydes and ketones. Under carefully controlled reaction conditions, second and third introduction of halogens into carbonyl compounds can be greatly suppressed, and high yields of monohalo compounds were obtained. The product ratios of this halogenation reactions can be best explained if the reactions are assumed to involve intermediate β-ketoselenenyl chlorides.