![88767-98-0,Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate,Benzenebutanoicacid, a-[[(trifluoromethyl)sulfonyl]oxy]-,ethyl ester, (R)-;Ethyl (R)-2-hydroxy-4-phenylbutyrate triflate;Ethyl (R)-[a-(trifluoromethylsulfonyl)oxy]benzenebutanoate;Ethyl 2(R)-[(trifluoromethylsulfonyl)oxy]-4-phenylbutyrate;Ethyl2-(R)-trifluoromethanesulfonyloxy-4-phenylbutanoate;alpha-[[(Trifluoromethyl)sulfonyl]oxy]-benzenebutanoic acid ethyl ester;](http://file1.lookchem.com/cas/reactions/2021/06/01/4712689.png)
Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate(88767-98-0)
- CAS Registry Number:
- 88767-98-0
- Synonyms:
- Benzenebutanoicacid, a-[[(trifluoromethyl)sulfonyl]oxy]-,ethyl ester, (R)-;Ethyl (R)-2-hydroxy-4-phenylbutyrate triflate;Ethyl (R)-[a-(trifluoromethylsulfonyl)oxy]benzenebutanoate;Ethyl 2(R)-[(trifluoromethylsulfonyl)oxy]-4-phenylbutyrate;Ethyl2-(R)-trifluoromethanesulfonyloxy-4-phenylbutanoate;alpha-[[(Trifluoromethyl)sulfonyl]oxy]-benzenebutanoic acid ethyl ester;
- Molecular Formula:
- C13H15F3O5S
- Molecular Weight:
- 340.32
- EINECS:
- 1308068-626-2
CAS No.:88767-98-0
Name: Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Related Suppliers
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate Manufacturer/High quality/Best price/In stock
Assay:98% Appearance:detailed see specifications Package:according to the clients requirement Storage:Store in dry, dark and ventilated place. Transportation:by sea or by air Application:It is an important raw material and intermediate used in Organic Synthesis, Pharmaceuticals, Agrochemicals and Dyestuff.
Min. Order:1Kilogram
Supplier:Dayang Chem (Hangzhou) Co.,Ltd. [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:99% Appearance:White powder Package:drum Storage:Store in a cool, ventilated warehouse Transportation:sea Application:Organic Chemicals
Min. Order:1Metric Ton
Supplier:HENAN NEW BLUE CHEMICAL CO.,LTD [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)-sulfonyl]-oxy]-butyrate CAS NO.88767-98-0
Assay:99% Appearance:powder or liquid Package:according to customer requirements Storage:store in dry dark and ventilated place Transportation:By Sea/Air/Courier Application:It is an important raw material.
Min. Order:10Gram
Supplier:Zibo Hangyu Biotechnology Development Co., Ltd [
China (Mainland)]
CAS No.88767-98-0 Ethyl (r)-4-phenyl-2-(((trifluoromethyl)sulfonyl)oxy)butyrate
Assay:99% Appearance:detailed see specifications Package:100g/bag,1kg/bag,25kg/drum,according to the clients requirement Storage:Store in dry, dark and ventilated place. Transportation:by air or by ocean shipping Application:An important raw material and intermediate used in Organic Synthesis, Pharmaceuticals
Min. Order:1Gram
Supplier:Hangzhou Zhongqi chem Co.,Ltd. [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:99% Package:According client's requirements Transportation:by sea/by air/by courier Application:Chemical products
Min. Order:1Kilogram
Supplier:Hangzhou ZeErRui Chemical Co., Ltd. [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate CAS:88767-98-0
Assay:99% Appearance:Brown powder Package:According to customer requirements Storage:Avoid light, ventilation and shade Transportation:Sea or Air Application:It is an important raw material and intermediate
Min. Order:1Gram
Supplier:Qingdao Beluga Import and Export Co., LTD [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:99% Appearance:Colorless liquid Package:25kg/drum or as you request Storage:Store Sealed in dry, Room Temperature Transportation:by sea or by air Application:As a reagent in organic synthesis reactions.
Min. Order:25Kilogram
Supplier:COLORCOM LTD. [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:99.0% Appearance:liquid Package:Grams, Kilograms Storage:Store the container tightly closed in a dry, cool and well-ventilated place. Store apart from foodstuff containers or incompatible materials. Transportation:According to customer request Application:For R&D and commerical use
Min. Order:100Gram
Supplier:Chemlyte Solutions [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:99% Appearance:white powder Package:10g/bag锛宱r as your request Storage:Stored in cool, dry and ventilation place; Away from fire and heat Transportation:as your request Application:Used as Pharmaceutical Intermediates
Min. Order:1Gram
Supplier:HANGZHOU YUNUO CHEMICAL CO.,LTD [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:99%min Appearance:white to off white powder Package:according to the clients requirement Storage:Store in dry, dark and ventilated place. Transportation:ocean shipping or air transportation Application:Pharmaceutical active ingredients Pharmaceutical intermediates etc
Min. Order:1Kilogram
Supplier:Afine Chemicals Limited [
China (Mainland)]
CAS No.88767-98-0 SAGECHEM/Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate/SAGECHEM/Manufacturer in China
Assay:99% Appearance:SAGECHEM/Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate/SAGECHEM/Manufacturer in China Package:packing on demand Storage:normal temperature Transportation:BY EXPRESS, AIR OR SEA Application:intermediate
Min. Order:0Metric Ton
Supplier:SAGECHEM LIMITED [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrat...
Assay:99% Appearance:solid or liquid Package:drum and bag Storage:in sealed air resistant place Transportation:by sea or air Application:for pharma use
Min. Order:0
Supplier:Kono Chem Co.,Ltd [
China (Mainland)]
CAS No.88767-98-0 (R)-4-Phenyl-2-[[(Trifluoromethyl)Sulfonyl]Oxy]Butyrate Ethyl
Assay:0.99 Appearance:white to off-white crystalline powder Package:25kg/drum;200kg/drum Storage:Keep away of light锛宑ool place Transportation:Sea/air/courier Application:Pharma Intermediate
Min. Order:0
Supplier:ORCHID CHEMICAL SUPPLIES LTD [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoroMethyl)sulfonyl]oxy]butyrate
Assay:98%min Appearance:To be subject to the object Package:Customized Transportation:Air Application:The refence standard products, for lab use, also we could produce bigger quantity on yr requirement.
Min. Order:0
Supplier:Hangzhou Dingyan Chem Co., Ltd [
China (Mainland)]
CAS No.88767-98-0 Benzenebutanoic acid, a-[[(trifluoromethyl)sulfonyl]oxy]-,ethyl ester, (aR)-
Assay:99% Transportation:By sea Application:Pharmaceutical industry
Min. Order:0
Supplier:Antimex Chemical Limied [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:98%min Package:25kg/drum,or as per customers'demand Transportation:air,sea,courier Application:API,or Intermediates,fine chemicals
Min. Order:0
Supplier:GIHI CHEMICALS CO.,LIMITED [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:95% Application:Chemical intermediate
Min. Order:0
Supplier:HANGZHOU TIANYE CHEMICALS CO., LTD. [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:99% Application:Used as pharmaceutical intermediate
Min. Order:0
Supplier:Shandong Hanjiang Chemical Co., Ltd. [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:98%min Appearance:Off-white to light yellow powder Package:According to the clients requirement. Storage:Keep in cool place. Transportation:Sea/air/courier Application:Pharmaceutical intermediates
Min. Order:0
Supplier:Hangzhou J&H Chemical Co., Ltd. [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:99% Package:box or opp package Storage:cool drum Transportation:air or sea Application:Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Min. Order:1Milligram
Supplier:weifang yangxu group co.,ltd [
China (Mainland)]
CAS No.88767-98-0 Benzenebutanoic acid, a-[[(trifluoromethyl)sulfonyl]oxy]-,ethyl ester, (aR)-
Assay:99% Package:drum Transportation:By Sea/Air/DHL Application:chemical
Min. Order:0
Supplier:Henan Wentao Chemical Product Co., Ltd. [
China (Mainland)]
CAS No.88767-98-0 (R)-4-Phenyl-2-[[(Trifluoromethyl)Sulfonyl]Oxy]Butyrate Ethyl
Assay:99% Appearance:detailed see specifications Package:25kg/drum;200kg/drum Storage:Keep away of light,cool place Transportation:Sea/air/courier Application:Chemical synthesis
Min. Order:0
Supplier:Xiamen Hisunny Chemical Co.,Ltd [
China (Mainland)]
CAS No.88767-98-0 (R)-4-Phenyl-2-[[(Trifluoromethyl)Sulfonyl]Oxy]Butyrate Ethyl
Assay:COA Appearance:COA Storage:in stock Application:MSDS/TDS
Min. Order:0
Supplier:Aecochem Corp. [
China (Mainland)]
CAS No.88767-98-0 Pharmaceutical Grade CAS 88767-98-0 with competitive price
Assay:99% Appearance:White powder Package: [Packaging]20mg, 50mg,100mg,1g,10g,100g,according to customers' requirements Storage: should be stored in a well-closed container at low temperature, keep away from moisture, heat and light. Transportation:1. Samples 1kg-10kg are shipped by international express. 2. 50kg-100kg of goods are transported by dedicated line logistics. 3. Cargo 100kg-1ton is transported by dedicated line logistics. Application:Chemical raw materials, pharmaceutical intermediates, cosmetic raw materials, etc.
Min. Order:1Kilogram
Supplier:Zhuozhou Wenxi import and Export Co., Ltd [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate CAS:88767-98-0
Assay:99%min Appearance:White Powder Package:100g/ bag, 2 kg/ bag, 25kg/ carton or as required Storage:Dry and cool place Transportation:By DHL, TNT, FedEx, HKEMS, UPS, Etc Application:For Pharmaceutical Raw Materials
Min. Order:10Gram
Supplier:Wuhan 90000 Lithium Industry and Trade Co., Ltd. [
China (Mainland)]
CAS No.88767-98-0 lower price High quality Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:99%min Appearance:colorless liquid Package:1kg/drum, 25kg/drum, 200kg/drum,500kg/drum Storage:Keep it in dry, cool and ventilated place Transportation:by sea or by air Application: For scientific research
Min. Order:1Kilogram
Supplier:Shanghai Seasonsgreen Chemical Co.,Ltd [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:99% Appearance:liquid or powder Package:according to the clients requirement Storage:Dry and Cool Place Transportation:UPS FedEx ,DHL,EXPRESS LINE Application:API
Min. Order:1Gram
Supplier:Shandong Mopai Biotechnology Co., LTD [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)-sulfonyl]-oxy]-butyrate
Assay:99% Haccp,,Halal,SC US FDA GMP ISO14001 Appearance:As per Certificate of analysis and our TDS, MSDS Package:Export standard and according to the clients requirement Storage:Store in dry, dark and ventilated place;ISO / Kosher /GMP licence commercial bulk capacity factory in China Transportation:By AIR or by SEA GMP licence / US-FDA,South Korea-KFDA Application:It is an important raw material and intermediate for chemical industry.
Min. Order:5Kiloliter
Supplier:Chemwill Asia Co., Ltd. [
China (Mainland)]
CAS No.88767-98-0 Benzenebutanoic acid, a-[[(trifluoromethyl)sulfonyl]oxy]-,ethyl ester, (aR)-
Assay:99% Appearance:white powder Package:drum or based on customers' requirement Storage:normal temperature storage Transportation:by sea, by air Application:We have different specifications for different applications
Min. Order:1Metric Ton
Supplier:Bluecrystal chem-union [
China (Mainland)]
CAS No.88767-98-0 (2R)-2-ethyl-2-hydroxy-4-phenylbutanoic acid; trifluoromethanesulfonic acid
Assay:97% Appearance:Powder or liquid Package:According to customer Storage:Store in a tightly closed container, in a cool and dry place. Transportation:Fedex,DHL,TNT,BY SEA and BY AIR Application:Medicinal Chemistry Biomedicine Pharmaceutical intermediates Chemistry experiment Biological experiments Chemical reagent For R&D use only.
Min. Order:10Milligram
Supplier:Amadis Chemical Co., Ltd. [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate 88767-98-0
Assay:95% Appearance:solid or liquid Package:Foil bag; Drum; Plastic bottle Storage:in sealed air resistant place Transportation:by sea or air Application:Pharma;Industry;Agricultural
Min. Order:0
Supplier:Hunan Russell Chemicals Technology Co.,Ltd [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:98.5% Appearance:white/off-white or light yellow Package:aluminum bottle,glass bottle,PTFE bottle,cardboard drum Storage:Store in cool and dry place, keep away from strong light and heat. Transportation:by courier, by air, by sea Application:This product can be used in food/pharmaceutical/cosmetical industry
Min. Order:0
Supplier:Suzhou Health Chemicals Co., Ltd. [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Appearance:95%+ Package:R&D,Pilot run Transportation:per client require
Min. Order:0
Supplier:Hunan chemfish Pharmaceutical co.,Ltd [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:98% Application:For research use only.
Min. Order:0
Supplier:BOC Sciences [
United States]
CAS No.88767-98-0 Ethyl (R)-4-Phenyl-2-(trifluoromethanesulfonyloxy)butyrate
Assay:98% Application:chemical reagent
Min. Order:0
Supplier:SHANDONG BENRITE NEW CHEMICAL MATERIALS CO.,LTD. [
China (Mainland)]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:99% Application:API
Min. Order:0
Supplier:NUTROCHEM- MANUFACTURE PLACE [
South Africa]
CAS No.88767-98-0 Ethyl (R)-4-phenyl-2-[[(trifluoromethyl)sulfonyl]oxy]butyrate
Assay:98% Package:According to the demand of customer Storage:Sealed, dry, microtherm , avoid light and smell. Transportation:by air or by sea Application:Organic synthesis
Min. Order:0
Supplier:Henan Allgreen Chemical Co.,Ltd [
China (Mainland)]
- Dayang Chem (Hangzhou) Co.,Ltd.
China (Mainland)- Tel:+86-571-88938639
- 9/F, Unit 2 Changdi Torch Building, 259# WenSan Road, Xihu District, Hangzhou City 310012, P.R.China
- weifang yangxu group co.,ltd
- China (Mainland)
- Tel:+08613666361637--
- No 5.dongfeng east street.gaoxin district.weifang city.
- SHANDONG BENRITE NEW CHEMICAL MATERIALS CO.,LTD.
- China (Mainland)
- Tel:86-0533-2866658
- Zibo Science and Technology Industrial Park, Zibo City,Shandong Province
- NUTROCHEM- MANUFACTURE PLACE
South Africa- Tel:27-838631975
- Stasieweg 019 Bethal Bethal Mpumalanga
- Shandong Mopai Biotechnology Co., LTD
- China (Mainland)
- Tel:+86-15965530500
- shandong
- HANGZHOU TIANYE CHEMICALS CO., LTD.
- China (Mainland)
- Tel:0571-85083592
- 1208# HuaCe Building-B,Wuchanggang Road,XIHU District,Hangzhou City,Zhejiang Province ,China
- Bluecrystal chem-union
- China (Mainland)
- Tel:+86-1895157
- Liang Xi Qu
- COLORCOM LTD.
- China (Mainland)
- Tel:+86-571-89007001
- ROOM 707, BUILDING 19, HUAXIA CENTER, CANGQIAN SUBDISTRICT, YUHANG DISTRICT, HANGZHOU CITY, ZHEJIANG PROVINCE, CHINA.
- Qingdao Beluga Import and Export Co., LTD
- China (Mainland)
- Tel:+8613854236000
- qingdao
- Shandong Hanjiang Chemical Co., Ltd.
- China (Mainland)
- Tel:+86 18369939125
- No.25A Qilu Industrial Park
- Zhuozhou Wenxi import and Export Co., Ltd
- China (Mainland)
- Tel:+86-13111626072
- Room 1710, Baoxin International Phase I, 19 Guanyun East Road, Zhuozhou, Hebei
- Zhuozhou Wenxi import and Export Co., Ltd
- China (Mainland)
- Tel:+86-13111626072
- Room 1710, Baoxin International Phase I, 19 Guanyun East Road, Zhuozhou, Hebei
- Chemlyte Solutions
- China (Mainland)
- Tel:+86-189 8945 5137
- Jian Qiao Community, 789 Shenhua Road, Xihu District, Hangzhou, China, 310000
- Henan Wentao Chemical Product Co., Ltd.
- China (Mainland)
- Tel:+86-370-2722992
- 32 Room, 5th Floor, Building 11, No. 6 Yinxing Road, High-tech Industrial Development Zone, Zhengzhou City, Henan Province
- Hangzhou ZeErRui Chemical Co., Ltd.
- China (Mainland)
- Tel:+86-571-82512721
- No 317,Jingling Road,Guali Town,Xiaoshan District
- Hunan Russell Chemicals Technology Co.,Ltd
- China (Mainland)
- Tel:0086-182-2994-0868
- Buiding4,Lugu Enterprise Plaza, Yuelu Distric
- Hangzhou Zhongqi chem Co.,Ltd.
- China (Mainland)
- Tel:0086-571-86976032
- Kangkang Gu 1010, Chun xiao road 61,Binjiang District 310052,Hangzhou city , China
- Shanghai Seasonsgreen Chemical Co.,Ltd
- China (Mainland)
- Tel:+86 156 1855 4368
- No.12, Lane 356, Chengnan Road, Chuansha Town, Shanghai
- Wuhan 90000 Lithium Industry and Trade Co., Ltd.
- China (Mainland)
- Tel:+86-027-83214688
- 666 Gaoxin Avenue, Donghu New Technology Development Zone, Wuhan City, Hubei Province, China
- Hunan chemfish Pharmaceutical co.,Ltd
- China (Mainland)
- Tel:0731-85567275
- Innovation center , Meixi Lake ,Yuelu district ,Changsha City, Hunan Province , China
- Zibo Hangyu Biotechnology Development Co., Ltd
- China (Mainland)
- Tel:86-15965530500
- Room1701, Tianxing Building,Licheng district, jinan, Shandong, China
- Chemwill Asia Co., Ltd.
- China (Mainland)
- Tel:021-51086038
- High-Tech Industrial park,Chemical Economical Development Zone,Xuzhou, Jiangsu-Province, P.R.China
- Henan Allgreen Chemical Co.,Ltd
- China (Mainland)
- Tel:+86-0371-87507775
- No 260 Dongming Road,Jinshui District
- Henan Allgreen Chemical Co.,Ltd
- China (Mainland)
- Tel:+86-0371-87507775
- No 260 Dongming Road,Jinshui District
- Aecochem Corp.
- China (Mainland)
- Tel:+86-592 599 8717-.
- No 611 Sishui Road,Huli
- HANGZHOU YUNUO CHEMICAL CO.,LTD
- China (Mainland)
- Tel:0571-83715115
- hangzhou
- ORCHID CHEMICAL SUPPLIES LTD
- China (Mainland)
- Tel:+86-571-85395792
- 607, North Zhongshan Road, Hangzhou 310000 China
- Kono Chem Co.,Ltd
- China (Mainland)
- Tel:86-29-86107037-8015
- No.11 Daqing Road,Lianhu District,Xi’an 710082,China
- Hangzhou Dingyan Chem Co., Ltd
- China (Mainland)
- Tel:86-571-87157530
- RM.1118,NO.1 Building, Baiyun Tower,Jianggan Area, Hangzhou city, China,310004
- Hangzhou Dingyan Chem Co., Ltd
- China (Mainland)
- Tel:86-571-87157530
- RM.1118,NO.1 Building, Baiyun Tower,Jianggan Area, Hangzhou city, China,310004
Other Product
- -
- -
- -
- -
- -
- -
- -
- -
- -
- (4S,6R)-6-{2-[(2-hydroxy-ethyl)-(4-methoxy-benzenesulfonyl)-amino]-ethoxy}-4-isopropyl-5,6-dihydro-4H-pyran-2-carboxylic acid allyl ester
- [1,4'-Bipiperidine]-1'-carboxylic acid, 4-(1H-indol-7-yl)-, ethyl ester
- 1,3,5-Tris(4-acetamidophenyl)penta-1,5-dione
- 1,5-Bis(3-aminophenyl)-3-(4-N,N-di-methylaminophenyl)penta-1,5-dione
- 1,5-Bis(4-acetamidophenyl)-3-phenylpenta-1,5-dione
- 1,5-Bis(4-aminophenyl)-3-(4-acetamido-phenyl)penta-1,5-dione
- 1,5-Bis(4-aminophenyl)-3-phenylpenta-1,5-dione