766-33-6

Basic information

• Product Name: 1,3-Dioxane, 2,5,5-trimethyl-
• Synonyms: 1,3-Dioxane, 2,5,5-trimethyl-;2,5,5-Trimethyl-1,3-dioxane
• CAS NO: 766-33-6
• Molecular Formula: C₇H₁₄O₂
• Molecular Weight: 130
• Mol File: 766-33-6.mol
• Article Data: 4

Chemical Properties

• Boiling Point: 132.883°C at 760 mmHg
• Flash Point: 33.968°C
• Appearance: /
• Density: 0.886g/cm³
• Vapor Pressure: 10.677mmHg at 25°C
• Refractive Index: 1.401
• CAS DataBase Reference: 1,3-Dioxane, 2,5,5-trimethyl-(CAS DataBase Reference)
• NIST Chemistry Reference: 1,3-Dioxane, 2,5,5-trimethyl-(766-33-6)
• EPA Substance Registry System: 1,3-Dioxane, 2,5,5-trimethyl-(766-33-6)

Safety Data

• Hazardous Substances Data: 766-33-6(Hazardous Substances Data)

Usage

General Description

1,3-Dioxane, 2,5,5-trimethyl- is a chemical compound that falls under the category of the cyclic ether family. The structure formula contains two oxygen atoms in a six-membered ring, with three methyl groups attached to one of the carbon atoms that isn't bonded to the oxygen atoms. As a cyclic acetal, this substance is known to be a versatile intermediate in organic synthesis. It is commonly used in the preparation of certain chemicals, solvent and additive products as a stabilizer. This chemical, like others in its class, can be harmful if not handled properly, with possible effects on human health and the environment.

InChI:InChI=1/C7H14O2/c1-6-8-4-7(2,3)5-9-6/h6H,4-5H2,1-3H3

Synthetic route

2-methyl-[1,3]dioxane (626-68-6) + 5,5-Dimethyl-5,6-dihydro-4H-1,3-dioxinium tetrafluoroborate → 2,5,5-trimethyl-1,3-dioxane (766-33-6) + 1,3-dioxanium tetrafluoroborate

Conditions	Yield
In dichloromethane at 20℃; for 3h;	A 79% B n/a

2,4-dimethyl-[1,3]dioxane (766-20-1) + 5,5-Dimethyl-5,6-dihydro-4H-1,3-dioxinium tetrafluoroborate → 2,5,5-trimethyl-1,3-dioxane (766-33-6) + 4-methyl-1,3-dioxanium

Conditions	Yield
In dichloromethane at 20℃; for 3h;	A 59% B n/a

2-methyl-1,3-dioxolane (497-26-7) + 5,5-Dimethyl-5,6-dihydro-4H-1,3-dioxinium tetrafluoroborate → 2,5,5-trimethyl-1,3-dioxane (766-33-6) + 1,3-dioxolanium tetrafluoroborate

Conditions	Yield
In dichloromethane at 20℃; for 3h;	A 54% B n/a

diethyl acetal (105-57-7) + (±)-2-sec-butyl-5,5-dimethyl-1,3,2-dioxaborinane → 2,5,5-trimethyl-1,3-dioxane (766-33-6) + diisobutyl isobutylboronate

Conditions	Yield
With zinc(II) chloride	A 5% B n/a

2,2,5,5-tetramethyl-1,3-dioxane (767-55-5) + 5,5-Dimethyl-5,6-dihydro-4H-1,3-dioxinium tetrafluoroborate → 2,5,5-trimethyl-1,3-dioxane (766-33-6) + C7H13O2(1+)*BF4(1-)

Conditions	Yield
In dichloromethane for 1h; Product distribution; Ambient temperature;	A 22 % Chromat. B n/a

diethyl acetal (105-57-7) + 2-isobutyl-5,5-dimethyl-1,3,2-dioxaborinane (145429-22-7) → 2,5,5-trimethyl-1,3-dioxane (766-33-6)

Conditions	Yield
With zinc(II) chloride transacetalation;

acetaldehyde (75-07-0) + 2,2-Dimethyl-1,3-propanediol (126-30-7) → 2,5,5-trimethyl-1,3-dioxane (766-33-6)

Conditions	Yield
sulfuric acid at 20℃; for 1h; Condensation;

diisobutyl ester of isobutylboronic acid (95093-83-7) → 2,5,5-trimethyl-1,3-dioxane (766-33-6)

Conditions	Yield
Multi-step reaction with 2 steps 1: ZnCl2 / 0.08 h / 130 °C 2: ZnCl2 View Scheme
Multi-step reaction with 2 steps 1: ZnCl2 / 0.08 h / 130 °C 2: ZnCl2 View Scheme
Multi-step reaction with 2 steps 1: ZnCl2 / 2 h / 130 °C 2: ZnCl2 View Scheme

2,5,5-trimethyl-1,3-dioxane (766-33-6) + isobutylmagnesium bromide (926-62-5) → 3-(1,3-Dimethyl-butoxy)-2,2-dimethyl-propan-1-ol

Conditions	Yield
In diethyl ether for 0.25h; Heating;	82%

2,5,5-trimethyl-1,3-dioxane (766-33-6) + allyl-trimethyl-silane (762-72-1) → [2,2-Dimethyl-3-(1-methyl-but-3-enyloxy)-propoxy]-trimethyl-silane (136367-83-4)

Conditions	Yield
With zinc(II) iodide at 100℃; for 4h;	75%

2,5,5-trimethyl-1,3-dioxane (766-33-6) + 1,3-dioxanium tetrafluoroborate → 2-methyl-[1,3]dioxane (626-68-6) + 5,5-Dimethyl-5,6-dihydro-4H-1,3-dioxinium tetrafluoroborate

Conditions	Yield
In dichloromethane at 20℃; for 3h;	A 52% B n/a

1-styrenyloxytrimethylsilane (13735-81-4) + 2,5,5-trimethyl-1,3-dioxane (766-33-6) → 1-phenylbut-2-en-1-one (495-41-0)

Conditions	Yield
With zinc(II) chloride In ethyl acetate at 50 - 60℃; for 0.4h;	33%

2,5,5-trimethyl-1,3-dioxane (766-33-6) + bis(ethylmercapto)dimethylsilane (7595-34-8) → 2,2-dimethylpropane-1,3-diol cyclic dimethylsilyl ether (14760-11-3)

Conditions	Yield
With sulfuric acid In toluene at 40℃; for 8h;	20%

2,5,5-trimethyl-1,3-dioxane (766-33-6) → 3-ethoxy-2,2-dimethyl-propionaldehyde (38216-86-3)

Conditions	Yield
at 380 - 400℃;

2,5,5-trimethyl-1,3-dioxane (766-33-6) + triisobutylaluminum (100-99-2) → 3-Ethoxy-2,2-dimethyl-propan-1-ol (78952-28-0) + 3-(1,3-Dimethyl-butoxy)-2,2-dimethyl-propan-1-ol

Conditions	Yield
With zinc(II) chloride In benzene for 2h; Product distribution; Mechanism; Heating; further reagents and conditions; regioselectivity of cleavage;

2,5,5-trimethyl-1,3-dioxane (766-33-6) + trifluoroacetic acid (76-05-1) → 3-Ethoxy-2,2-dimethyl-propan-1-ol (78952-28-0) + 2,2-dimethyl-1,3-diethoxypropane (78952-33-7) + Trifluoro-acetic acid 3-ethoxy-2,2-dimethyl-propyl ester (78952-31-5) + Trifluoro-acetic acid 2,2-dimethyl-3-(2,2,2-trifluoro-acetoxy)-propyl ester (54833-26-0)

Conditions	Yield
With triethylsilane; hydride ion Product distribution; Mechanism; Ambient temperature; without addition of hydride ion;

2,5,5-trimethyl-1,3-dioxane (766-33-6) + ethenyltrimethylsilane (754-05-2) → Acetic acid 2,2-dimethyl-5-trimethylsilanyl-pentyl ester

Conditions	Yield
With tert.-butylhydroperoxide at 140℃; for 2.5h;

Upstream product

• 497-26-7 2-methyl-1,3-dioxolane 
• 626-68-6 2-methyl-[1,3]dioxane 
• 766-20-1 2,4-dimethyl-[1,3]dioxane 
• 767-55-5 2,2,5,5-tetramethyl-1,3-dioxane 
• 75-07-0 acetaldehyde 
• 126-30-7 2,2-Dimethyl-1,3-propanediol 
• 105-57-7 diethyl acetal 
• 95093-83-7 diisobutyl ester of isobutylboronic acid 
• 145429-22-7 2-isobutyl-5,5-dimethyl-1,3,2-dioxaborinane 

Downstream Products

• 14760-11-3 2,2-dimethylpropane-1,3-diol cyclic dimethylsilyl ether 
• 626-68-6 2-methyl-[1,3]dioxane 
• 78952-28-0 3-Ethoxy-2,2-dimethyl-propan-1-ol 
• 78952-33-7 2,2-dimethyl-1,3-diethoxypropane 
• 78952-31-5 Trifluoro-acetic acid 3-ethoxy-2,2-dimethyl-propyl ester 
• 54833-26-0 Trifluoro-acetic acid 2,2-dimethyl-3-(2,2,2-trifluoro-acetoxy)-propyl ester 
• 495-41-0 1-phenylbut-2-en-1-one 

Relevant articles and documents

Identification of 1,3-dioxanes and 1,3-dioxolanes as malodorous compounds at trace levels in river water, groundwater, and tap water

A study of organic compounds imparting odor problems in river waters and groundwaters has been conducted. The Tordera aquifer located in Barcelona and Girona (NE Spain) is the water supply reserve for many seasonally crowded villages on the coast. Closed loop stripping analysis (CLSA) and flavor profile analysis (FPA) have been employed as analytical tools to identify the compounds responsible for the odor complaints. The feasibility of purge-and- trap (P and T) has also been evaluated. The 2-alkyl-5,5-dimethyl-1,3-dioxanes and 2-alkyl-4-methyl-1,3-dioxolanes were the most significant compounds identified in river water and groundwater with a threshold odor of 10 ng/L for 2-ethyl-5,5-dimethyl-1,3-dioxane (2EDD), the most malodorous compound. The analyses were carried out by HRGC/MS, and the synthesized 1,3-dioxanes and dioxolanes were characterized by CI-MS and EI-MS/MS techniques. A company, currently manufacturing saturated and unsaturated polyester resins, located in the upper course of the river, produced these compounds as byproducts during the synthesis of resins. The pollution by dioxanes and dioxolanes affected all the aquifer and slowly diminished to the ppt levels when the company was forced to correctly treat their wastewaters. Additional examples of the presence of dioxanes and dioxolanes in wastewaters of other resin plants and also tap water of Barcelona are shown. A study of organic compounds imparting odor problems in river waters and groundwaters has been conducted. The Tordera aquifer located in Barcelona and Girona (NE Spain) is the water supply reserve for many seasonally crowded villages on the coast. Closed loop stripping analysis (CLSA) and flavor profile analysis (FPA) have been employed as analytical tools to identify the compounds responsible for the odor complaints. The feasibility of purge-and-trap (P&T) has also been evaluated. The 2-alkyl-5,5-dimethyl-1,3-dioxanes and 2-alkyl-4-methyl-1,3-dioxolanes were the most significant compounds identified in river water and groundwater with a threshold odor of 10 ng/L for 2-ethyl-5,5-dimethyl-1,3-dioxane (2EDD), the most malodorous compound. The analyses were carried out by HRGC/MS, and the synthesized 1,3-dioxanes and dioxolanes were characterized by CI-MS and EI-MS/MS techniques. A company, currently manufacturing saturated and unsaturated polyester resins, located in the upper course of the river, produced these compounds as byproducts during the synthesis of resins. The pollution by dioxanes and dioxolanes affected all the aquifer and slowly diminished to the ppt levels when the company was forced to correctly treat their wastewaters. Additional examples of the presence of dioxanes and dioxolanes in wastewaters of other resin plants and also tap water of Barcelona are shown.

REACTION OF CYCLIC ACETALS WITH 1,3-DIOXANIUM SALTS

The products from reaction of 1,3-dioxacycloalkanes with 1,3-dioxanium tetrafluoroborates are a new pair of compounds, i.e., 1,3-dioxacycloalkanium tetrafluoroborate and 1,3-dioxane.The reaction is reversible and takes place by a transacetalization mechanism.