• Elastomers and Composites
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• 제54권2호
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• pp.110-117
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• 2019

The characterization of the ozone oxidation for raw natural rubber (NR) was investigated under controlled conditions through image and fourier transform infrared (FT-IR) analysis. The ozone oxidation was performed on a transparent thin film of raw NR coated on a KBr window in a dark chamber at $40^{\circ}C$ under low humidity conditions to completely exclude thermal, moisture, or light oxidation. The ozone concentration was set at 40 parts per hundred million (pphm). Before or after exposure to ozone, the image of the thin film for raw NR was observed at a right or tilted angle. FT-IR absorption spectra were measured in the transmission mode according to ozone exposure time. The ozone oxidation of NR was determined by the changes in the absorption peaks at 1736, 1715, 1697, and $833cm^{-1}$, which were assigned to an aldehyde group (-CHO), a ketone group (-COR), an inter-hydrogen bond between carbonyl group (-C=O) from an aldehyde or a ketone and an amide group (-CONH-) of protein, and a cis-methine group ($is-CCH_3=CH-$, respectively. During ozone exposure period, the results indicated that the formation of the carbonyl group of aldehyde or ketone was directly related to the decrement of the double bond of cis-1,4-polyisoprene. Only carbonyl compounds such as aldehydes or ketones seemed to be formed through chain scission by ozone. Long thin cracks with one orientation at regular intervals, which resulted in consecutive chain scission, were observed by image analysis. Therefore, one possible two-step mechanism for the formation of aldehyde and ketone was suggested.

• Applied Biological Chemistry
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• 제37권3호
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• pp.216-220
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• 1994

염소 및 이소프로필알콜이 리간드로 작용하는 여러 형태의 anisyltitanium 화합물을 합성 분리하였다. 즉 anisyltitanium 화합물을 합성한 뒤 해당 염화티탄 화합물과 치환시킴으로써 용이하게 유기티탄화합물을 합성, 순수분리 하였다. 이 화합물들은 아르곤하에서 또 낮은 온도 $0^{\circ}C$ 이하에서 대체로 안정하였으며, 카르보닐 화합물과 용이하게 첨가반응을 일으켜 알콜을 형성하였다. 화학선택성 조사에서 이 화합물들은 낮은 온도에서 알데히드-케톤 혼합물과 반응시킬 때 완벽한 알데히드 선택성을 나타내어 알데히드-케론의 두 가지 카르보닐 화합물 중 반응성이 큰 알데히드에 anisyl기가 선택적으로 첨가됨을 알았다.

• 분석과학
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• 제9권4호
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• pp.399-405
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• 1996

참기름 중의 향기성분을 연속수증기증류법(SDE)과 동적헤드스페이스법(DHS)으로 포집하여 GC와 GC-MSD로 동정하였다. SDE로 분석하였을 때 alcohol 6종, aldehyde 6종, ketone 및 acid류 5종, furan 및 phenol류 4종, pyrazine 화합물 12종, pyridine 및 thiazole류 4종, 기타 9종으로 총 46종이 확인되었다. DHS로 분석한 경우 alcohol 3종, aldehyde 6종, ketone, furan 및 phenol류 6종, pyrazine류 12종, pyridine 및 thiazole 4종, 기타 5종으로 모두 36종이 확인되었다. 대부분의 화합물이 SDE법에서 분리된 것이었으나 1-hexanol, pentanal, dimethylsulfide등은 DHS법에 의해서만 분리되었다.

• Bulletin of the Korean Chemical Society
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• 제23권9호
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• pp.1272-1287
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• 2002

Sonochemical Reformatsky reaction of aldehydes or ketones with ethyl bromoacetate in the presence of indium afforded $\beta-hydroxyesters$ in good to excellent yields under mild conditions. 2- or 3-Hydroxybenzaldehyde that contains an acidic hydrogen r eacted with ethyl bromoacetate to provide the desired compounds with the same efficiency. In the case of ethyl 2-bromopropanoate and ethyl 2-bromo-2-methylpropanoate, the desired products were obtained in good yields. Reaction of aldehyde with indium reagent in the presence of ketone group proceeded chemoselectively.

• Bulletin of the Korean Chemical Society
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• 제5권1호
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• pp.32-37
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• 1984

The photoreaction of 2, 3-benzo-1, 1-diphenyl (or dimethyl)-1-sila-2-cyclobutene (9 or 10) with an aldehyde or ketone results in 1:1 cycloadduct of [4 + 2] type. In the reactions of 2, 3-benzo-1, 1-dimethyl-1-sila-2-cyclobutene (10) with acetone and butanone, another 1:1 adducts (13) were also formed, respectively. The following facts indicate that the formation of adduct involves an attack of a triplet carbonyl compound on the silicon of the benzosilacyclobutene, an $S_H2$ process. (1) Even when the reaction of 9 with acetophenone was carried out under conditions such that more than 99% of incident light was absorbed only by acetophenone using the filter solution of aq. cupric sulfate, the same adduct was still formed. (2) When the reaction of 9 with acetone was carried out under oxygen atmosphere, only trace amount of adduct was formed.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2419-2421
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• 2009

A simple and efficient method has been developed for Knoevenagel condensation between aldehydes or ketones and active methylene group by stirring in methylene chloride at 60 ${^{\circ}C}$ under heterogeneous conditions using silica supported ammonium acetate. The products are obtained in excellent yields and are in a state of high purity. The structures of the products were confirmed by IR, $^1H$ NMR and mass spectral data and comparison with authentic samples available commercially.

• Journal of the Korean Wood Science and Technology
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• 제42권4호
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• pp.357-366
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• 2014

백합나무 판재를 벽판재로 이용하기 위해 백합나무의 생재와 건조재에 대한 휘발성유기화합물(VOCs)과 알데히드류 방출 특성을 검토하였다. VOCs 및 formaldehyde를 포함한 aldehyde류의 방출량 측정은 다중이용시설 등의 실내공기질 관리법에 공시된 20 ${\ell}$ Chamber법에 따라 실시하였다. 백합나무의 생재 및 건조재에서는 30여 가지 이상의 VOCs가 검출되었다. 백합나무의 Total VOC 구성 비율 가운데 천연VOC (NVOC)의 비율은 11.1%로 다른 침엽수종과 비교하여 낮게 나타났다. 백합나무의 aldehyde류 분석 결과, 심재 및 변재에서 같은 3종(acetaldehyde, ketone, propionaldehyde)이 검출되었으며, formaldehyde의 방출량은 $4.01{\mu}g/m^3$ 이하로 나타났다. m-Tolualdehyde의 경우 백합나무 건조재의 심재에서만 $33.6{\mu}g/m^3$의 방출량을 보였으며, 심재와 변재 모두 ketone의 방출량이 가장 높게 나타났다. 백합나무 특유의 역한 냄새는 acetaldehyde와 propionaldehyde와 기타 VOCs에 의한 것으로 추정된다. 건조한 백합나무에서는 휘발성이 강한 ketone의 방출량이 증가하였다.

• 한국조리학회지
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• 제13권1호
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• pp.119-128
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• 2007

식품의 조리과정 중에 부산물로 나오는 갑각류 폐기물을 이용하여 소스를 제조하여 canister system을 이용하여 농축한 후 GC/MSD를 이용해 휘발성 성분을 동정하였다. 그 결과 총 휘발성 성분의 개수는 72종이었으며 그 중 새우를 사용하여 만든 소스의 휘발성 성분이 45개로 가장 많았다. 새우 소스의 휘발성 성분은 10종의 alkane, 4종의 ketone, 3종의 aldehyde 및 7종의 alcohol이었으며 3-methyl-2-butanone, 2-pentanamine, isobutane, 3- methyl-butanal, furan, carbon disulfide, dimethyl sulfide가 주요한 성분이었다. 꽃게 소스에서는 18개의 휘발성 성분이 동정되었고, 4종의 alcohol류, 5종의 alkane류, 3종의 aldehyde류 및 ketone, acid와 amine이 각각 1종 검출되었으며, 2-methoxy ethanol, trimethyloxirane, 3-buten-1-ol이 꽃게 소스에서 주요한 휘발성 성분으로 나타났다. 바다가재 머리부분을 이용한 소스에서 16종의 휘발성 성분이 동정되었으며 alkane류 2종, aldehyde와 alcohol이 각각 1종씩 동정되었고 formic acid, 1-propanethiol, $\beta$-pinene, allyl sulfide가 주요한 향기 성분으로 나타났다. 바다가재 껍질을 이용한 소스에서 휘발성 성분이 18종 검출되었으며, acid류, pentane, 3-methyl 1-butanol 및 2, 4-dimethyl- 3-pentanone이 주요한 휘발성 성분인 것을 알 수 있었다.

• 통합자연과학논문집
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• 제1권3호
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• pp.192-194
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• 2008

A series of non-free hydride reducing systems containing boron or aluminum atom, which possess no metal-hydride bond but an available hydrogen at a branched ${\beta}$-position, has been applied to the selective reduction (chemo--, regio-, and stereoselective reduction) of organic compounds. The systems, comprised of diisopinocampheylborane and diisobutylalane derivatives, exhibited almost perfect selectivities in the reduction of aldehydes and ketones. The characteristics features of this systems leading to a perfect transformation have been depicted in this report, especially in the 1) Reduction of ${\alpha}$,${\beta}$-Unsaturated Carbonyl Compounds to Allylic Alcohols via 1,2-Reduction, 2) Chemoselective Reduction between Structurally Different Carbonyl Compounds, and 3) Stereoselective Reduction of Cyclic Ketones.

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