2-乙基-2-甲基-1,3-二氧戊环

2-乙基-2-甲基-1,3-二氧戊环用途

2-甲基-2-乙基-1,3-二氧杂环戊烷(MED)在有机合成中主要被用作缩醛化交换试剂，将底物分子中的醛酮官能团转变成为乙二醇的缩醛或者缩酮。

MED与醛在酸催化剂的存在下发生缩醛交换反应，生成新的乙二醇的缩醛。对甲苯磺酸或者樟脑磺酸是该反应最常用的催化剂。与直接使用乙二醇在酸性条件下加热脱水相比较，该反应可以在非常温和的条件下进行。多数情况下在室温下搅拌数小时即可完成，这对那些有酸敏官能团的底物相当重要 (式1)。

在几乎相同的条件下，MED可以方便地将酮转变成乙二醇的缩酮。CH₂Cl₂或者苯是最常用的反应溶剂，酸敏性很高的叔醇在此条件下也不受到明显的影响 (式2)。该反应也可以使用过量的MED作为反应溶剂 (式3)。值得推荐的方法是在使用过量的MED的同时，加入少量的乙二醇为催化剂可以得到更好的产率 (式4)。

与二甲基-1,3-二氧杂环戊烷相比较，MED与含有多个酮官能团底物的反应具有更高的区域选择性。底物的结构对选择性的影响主要来自于酮官能团的立体位阻的影响。六元环优先于五元环 (式5)，位阻小的优先于位阻大的 (式6)。

2-乙基-2-甲基-1,3-二氧戊环名称

[ CAS 号 ]:
126-39-6

[ 中文名 ]:
2-乙基-2-甲基-1,3-二氧杂烷

[ 英文名 ]:
2-ETHYL-2-METHYL-1,3-DIOXOLANE

[中文别名 ]:

[英文别名 ]:

2,2-ethylenedioxybutane
2-ethyl-2-methyl-3-dioxolane
2-Methyl-2-ethyldioxolane
EINECS 204-785-2
2-BUTANONE CYCLIC ETHYLENE ACETAL
MFCD00014108
2-Methyl-2-ethyl-1,3-dioxolane
Ethyleneacetic acid.
2-Ethyl-2-methyldioxolane
2-BUTANONE ETHYLENE ACETAL

2-乙基-2-甲基-1,3-二氧戊环物理化学性质

[ 密度 ]:
0.929 g/mL at 25 °C(lit.)

[ 沸点 ]:
116-117 °C(lit.)

[ 分子式 ]:
C₆H₁₂O₂

[ 分子量 ]:
116.15800

[ 闪点 ]:
55 °F

[ 精确质量 ]:
116.08400

[ PSA ]:
18.46000

[ LogP ]:
1.15940

[ 外观性状 ]:
液体;Colorless to Almost colorless clear liquid

[ 蒸汽压 ]:
21.9mmHg at 25°C

[ 折射率 ]:
n20/D 1.409(lit.)

[ 储存条件 ]:
Refrigerator

2-乙基-2-甲基-1,3-二氧戊环MSDS

2-乙基-2-甲基-1,3-二氧戊环毒性和生态

CHEMICAL IDENTIFICATION

RTECS NUMBER :: JH7700000

CHEMICAL NAME :: 1,3-Dioxolane, 2-ethyl-2-methyl-

CAS REGISTRY NUMBER :: 126-39-6

BEILSTEIN REFERENCE NO. :: 0102815

LAST UPDATED :: 199701

DATA ITEMS CITED :: 6

MOLECULAR FORMULA :: C6-H12-O2

MOLECULAR WEIGHT :: 116.18

WISWESSER LINE NOTATION :: T5O COTJ B2 B1

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :: Standard Draize test

ROUTE OF EXPOSURE :: Administration onto the skin

SPECIES OBSERVED :: Rodent - rabbit

REFERENCE :: 85JCAE "Prehled Prumyslove Toxikologie; Organicke Latky," Marhold, J., Prague, Czechoslovakia, Avicenum, 1986 Volume(issue)/page/year: -,797,1986

TYPE OF TEST :: Standard Draize test

ROUTE OF EXPOSURE :: Administration into the eye

SPECIES OBSERVED :: Rodent - rabbit

REFERENCE :: 85JCAE "Prehled Prumyslove Toxikologie; Organicke Latky," Marhold, J., Prague, Czechoslovakia, Avicenum, 1986 Volume(issue)/page/year: -,797,1986 ** ACUTE TOXICITY DATA **

TYPE OF TEST :: LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :: Oral

SPECIES OBSERVED :: Rodent - rat

DOSE/DURATION :: 2830 uL/kg

TOXIC EFFECTS :: Details of toxic effects not reported other than lethal dose value

REFERENCE :: AIHAAP American Industrial Hygiene Association Journal. (AIHA, 475 Wolf Ledges Pkwy., Akron, OH 44311) V.19- 1958- Volume(issue)/page/year: 23,95,1962

TYPE OF TEST :: LCLo - Lowest published lethal concentration

ROUTE OF EXPOSURE :: Inhalation

SPECIES OBSERVED :: Rodent - rat

DOSE/DURATION :: 4000 ppm/4H

TOXIC EFFECTS :: Details of toxic effects not reported other than lethal dose value

REFERENCE :: AIHAAP American Industrial Hygiene Association Journal. (AIHA, 475 Wolf Ledges Pkwy., Akron, OH 44311) V.19- 1958- Volume(issue)/page/year: 23,95,1962

TYPE OF TEST :: LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :: Administration onto the skin

SPECIES OBSERVED :: Rodent - rabbit

DOSE/DURATION :: 10 mL/kg

TOXIC EFFECTS :: Details of toxic effects not reported other than lethal dose value

REFERENCE :: AIHAAP American Industrial Hygiene Association Journal. (AIHA, 475 Wolf Ledges Pkwy., Akron, OH 44311) V.19- 1958- Volume(issue)/page/year: 23,95,1962

2-乙基-2-甲基-1,3-二氧戊环安全信息

[ 符号 ]:

GHS02, GHS07

[ 信号词 ]:
Danger

[ 危害声明 ]:
H225-H315-H319-H332-H335

[ 警示性声明 ]:
P210-P261-P305 + P351 + P338

[ 个人防护装备 ]:
Eyeshields;Faceshields;full-face respirator (US);Gloves;multi-purpose combination respirator cartridge (US);type ABEK (EN14387) respirator filter

[ 危害码 (欧洲) ]:
F: Flammable;Xi: Irritant;

[ 风险声明 (欧洲) ]:
R11;R36

[ 安全声明 (欧洲) ]:
S16-S26-S36/37/39-S38

[ 危险品运输编码 ]:
UN 1993 3/PG 2

[ WGK德国 ]:
3

[ RTECS号 ]:
JH7700000

[ 包装等级 ]:
II

[ 危险类别 ]:
3.1

[ 海关编码 ]:
2932999099

2-乙基-2-甲基-1,3-二氧戊环合成路线

2-乙基-2-甲基-1,3-二氧戊环海关

[ 海关编码 ]: 2932999099

[ 中文概述 ]:
2932999099. 其他仅含氧杂原子的杂环化合物. 增值税率:17.0%. 退税率:13.0%. 监管条件:无. 最惠国关税:6.5%. 普通关税:20.0%

[ 申报要素 ]: 品名, 成分含量, 用途

[ Summary ]:
2932999099. other heterocyclic compounds with oxygen hetero-atom(s) only. VAT:17.0%. Tax rebate rate:13.0%. . MFN tariff:6.5%. General tariff:20.0%

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