4511-42-6

Basic information

• Product Name: L-Lactide
• Synonyms: L-3,6-Dimethyl-1,4-dioxane-2,5-dione;1,4-Dioxane-2,5-dione, 3,6-dimethyl-, (3S,6S)-;3,6-dimethyl-1,4-dioxane-2,5-quinone;L-(-)-Lactide ,99%;L,L-Dilactide;L-3,6-DiMethyl-p-dioxane-2,5-dione;LL-Lactide;L-(-)-Dilactide (3S,6S)-(-)-3,6-Dimethyl-1,4-dioxane-2,5-dione
• CAS NO: 4511-42-6
• Molecular Formula: C₆H₈O₄
• Molecular Weight: 144.13
• EINECS: 224-832-0
• Product Categories: Chiral Building Blocks;Dioxanes;Dioxanes & Dioxolanes;Functional Materials;Glycidyl Compounds, etc. (Chiral);Lactones & Lactides (for High-Performance Polymer Research);Reagent for High-Performance Polymer Research;Synthetic Organic Chemistry
• Mol File: 4511-42-6.mol
• Article Data: 35

Chemical Properties

• Melting Point: 92-94 °C(lit.)
• Boiling Point: 255°C
• Flash Point: 150.6 °C
• Appearance: Crystalline flake object
• Density: 1.186 g/cm³
• Vapor Pressure: 0.0028mmHg at 25°C
• Refractive Index: 1.4475
• Storage Temp.: 2-8°C
• Solubility: Soluble in chloroform, and methanol. Slightly soluble in benzene
• Water Solubility: 16.7g/L at 20℃
• Sensitive: Moisture Sensitive
• Stability: Hygroscopic
• BRN: 82124
• CAS DataBase Reference: L-Lactide(CAS DataBase Reference)
• NIST Chemistry Reference: L-Lactide(4511-42-6)
• EPA Substance Registry System: L-Lactide(4511-42-6)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38-36
• Safety Statements: 26-37/39
• WGK Germany: 3
• TSCA: Yes
• Hazardous Substances Data: 4511-42-6(Hazardous Substances Data)

Usage

Chemical Properties

White crystal

Uses

(3S)-cis-3,6-Dimethyl-1,4-dioxane-2,5-dione may be used in the synthesis of optically active terpyridine containing poly(L-lactide)s, polydisperse lactic acid oligomers, bicyclic and tricyclic lactide derivatives.

Flammability and Explosibility

Nonflammable

Purification Methods

This is the cyclic dilactone of lactic acid. The (±)-cis-racemate has been distilled with b 142o/8mm; the distillate which solidifies gives yellow needles on recrystallisation from EtOH with m 128o, from Et2O with m 129o, or CHCl3 with m 126o , 1720-1740 cm-1. It hydrolyses in cold max H2O. [Carothers et al. J Am Chem Soc 54 772 1932]. A trans-form (probably RS,SR) has been reported which crystallises from Et2O with m 42-43o [Hummel et al. Acta Cryst (Sect B) 38 1679 1982]. The R,R -(+)-lactide has b 150o/2mm and crystallises from Et2O with m 95o , or m 96.5 -97.5o (from CHCl3) or m 97.7o (from EtOAc) and [] D +297o (c 1.2, *C6H6). The S,S-(-)-lactide has b 150o/2.5mm and crystallises from EtOAc with m 98.7o, or m 95o (from CHCl3) or m 96.5-97.5o (from CCl4) and []D -297o (c 1.2, *C6H6). [Toniolo et al. J Org Chem 35 6 1970, Beilstein 19 H 154, 19 I 179, 19 II 176, 19 IV 1927, 19/5 V 10.]

InChI:InChI=1/C6H8O4/c1-3-5(7)10-4(2)6(8)9-3/h3-4H,1-2H3/t3-,4+

Synthetic route

Reaxys ID: 11369849 → L,L-dilactide (4511-42-6)

Conditions	Yield
at 60 - 320℃; for 0.35 - 0.433333h; Product distribution / selectivity; Pyrolysis;	100%
at 280℃; for 2h; Product distribution / selectivity; Pyrolysis;	95.3%

Reaxys ID: 11385251 → L,L-dilactide (4511-42-6)

Conditions	Yield
tin octylate at 200℃; under 5 Torr; Product distribution / selectivity;	99.3%
at 200℃; under 5 Torr; Product distribution / selectivity;	99.3%
at 200℃; under 5 Torr; Product distribution / selectivity;
at 200℃; under 5 Torr; Product distribution / selectivity;
at 210℃; under 4 Torr; Product distribution / selectivity;

stannous lactate → L,L-dilactide (4511-42-6)

Conditions	Yield
With benzylurea at 100 - 180℃; under 1 Torr; for 2h; Temperature; Reagent/catalyst; Pressure;	96.72%

L-Lactic acid (79-33-4) → L,L-dilactide (4511-42-6)

Conditions	Yield
In water at 240℃; under 760.051 Torr; Inert atmosphere; Autoclave;	94%
Stage #1: L-Lactic acid With 1-docosanol; 3-chloropyridinium trifluoromethanesulfonate at 140℃; under 25 Torr; for 12h; Stage #2: at 160℃; under 1 Torr; for 3h; Reagent/catalyst; Pressure; Temperature; Time;	80%
Stage #1: L-Lactic acid With 1-docosanol; 3-chloropyridinium trifluoromethanesulfonate In water at 140℃; under 30.003 Torr; for 12h; Stage #2: In water at 160℃; under 0.99985 Torr; for 3h; Reagent/catalyst;	79%

(S)-Ethyl lactate (687-47-8) → L,L-dilactide (4511-42-6)

Conditions	Yield
titanium(IV) tetraethanolate; Triethylene glycol dimethyl ether at 120℃; under 50 Torr; for 7.5h; Inert atmosphere;	85.5%
Stage #1: (S)-Ethyl lactate With cerium(III) chloride heptahydrate In water Inert atmosphere; Stage #2: for 4h; Reagent/catalyst;	52%
With Triethylene glycol dimethyl ether; titanium(IV) tetraethanolate at 120℃; for 6h; Product distribution / selectivity;

L-Lactic acid (79-33-4) + 1-docosanol (661-19-8) → 2-docosene (908335-80-8) + methyl 2-docosyloxypropionate + L,L-dilactide (4511-42-6)

Conditions	Yield
Stage #1: L-Lactic acid; 1-docosanol With 3-chloropyridinium trifluoromethanesulfonate at 140℃; under 25 Torr; for 12h; Stage #2: at 160℃; under 1 Torr; for 3h; Stage #3: With methanol; potassium carbonate Reagent/catalyst; Pressure; Temperature; Time;	A n/a B n/a C 80%

L-Lactic acid (79-33-4) + (-)-menthol (2216-51-5) → L-menthyl L-lactoyl L-lactate (923031-01-0) + L-menthyl L-lactoyl L-lactoyl L-lactate (923031-02-1) + (1R,2S,5R)-menthyl (S)-(-)-lactate (61597-98-6) + L,L-dilactide (4511-42-6)

Conditions	Yield
In n-heptane; water at 128℃; for 32h; Product distribution / selectivity; Heating / reflux;	A 24.6% B 0.4% C 67.7% D 0.6%
sulfuric acid In n-heptane at 119℃; for 2h; Product distribution / selectivity;	A 32.2% B 1.9% C 57.6% D 0.4%
sodium hydrogen sulfate In n-heptane at 93 - 123℃; for 17h; Product distribution / selectivity; Heating / reflux;	A 36.5% B 5.6% C 48.7% D 4.8%

Reaxys ID: 11369848 → hexalactide + trilactide (859046-55-2) + C12H16O8 + C15H20O10 (859046-57-4) + C21H28O14 + (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) + L,L-dilactide (4511-42-6) + D-lactide (13076-17-0)

Conditions	Yield
at 60 - 400℃; for 0.566667h; Product distribution / selectivity; Pyrolysis;	A 4.51% B 3.26% C 5.59% D 6.02% E 1.88% F 18.28% G n/a H n/a

...Expand

Reaxys ID: 11369849 → hexalactide + trilactide (859046-55-2) + C12H16O8 + C15H20O10 (859046-57-4) + (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) + L,L-dilactide (4511-42-6) + D-lactide (13076-17-0)

Conditions	Yield
at 60 - 400℃; for 0.566667h; Product distribution / selectivity; Pyrolysis;	A 0.46% B 0.5% C 1.65% D 0.75% E 12.17% F n/a G n/a

methyl lactate (547-64-8) → methanol (67-56-1) + DP2 + DP3 + DP4 + L,L-dilactide (4511-42-6)

Conditions	Yield
Amberlys 36 resin at 104 - 115℃; under 25 - 80 Torr; for 28h; Heating / reflux;	A n/a B 7.4% C 0.3% D 0% E 0%

Reaxys ID: 11369849 → (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) + L,L-dilactide (4511-42-6) + D-lactide (13076-17-0)

Conditions	Yield
at 60 - 400℃; for 0.433333 - 0.566667h; Product distribution / selectivity; Pyrolysis;	A 6.08% B n/a C n/a

Reaxys ID: 11369849 → C12H16O8 + C15H20O10 (859046-57-4) + L,L-dilactide (4511-42-6) + D-lactide (13076-17-0)

Conditions	Yield
at 60 - 300℃; for 0.4h; Product distribution / selectivity; Pyrolysis;	A 0.28% B 0.2% C n/a D n/a

(S,S)-2-[(2-hydroxypropanoyl)oxy]propanoic acid (923-17-1) → L,L-dilactide (4511-42-6)

Conditions	Yield
Stage #1: (S,S)-2-[(2-hydroxypropanoyl)oxy]propanoic acid With 1,3,5-trichloro-2,4,6-triazine In acetone at 20℃; Stage #2: With triethylamine In acetone for 1h; Further stages.;

sec-phenethyl O-lactoyllactate (620627-85-2) → L,L-dilactide (4511-42-6) + [Y[2,2'-(1,4-dithiabutanediyl)-bis(4-methyl-6-tert-butylphenolato)]{N(SiHMe2)2}(THF)]

Conditions	Yield
Multi-step reaction with 2 steps 1.1: 100 percent / hydrogen / Pd/C / ethanol / 20 °C 2.1: cyanuric chloride / acetone / 20 °C 2.2: Et3N / acetone / 1 h View Scheme

poly(L-lactic acid) → LACTIC ACID (849585-22-4) + (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) + L,L-dilactide (4511-42-6) + D-lactide (13076-17-0)

Conditions	Yield
tin(II) octanoate at 210 - 230℃; under 22.5023 Torr; for 1 - 2h; Product distribution / selectivity;
zinc stearate at 210 - 230℃; under 22.5023 Torr; for 1 - 2h; Product distribution / selectivity;
tin(II) octanoate at 210 - 230℃; under 22.5023 Torr; for 1 - 2h; Product distribution / selectivity;

L-lactic acid oligomer → (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) + L,L-dilactide (4511-42-6)

Conditions	Yield
Stage #1: L-lactic acid oligomer at 140℃; for 730.5h; Stage #2: tin(II) octanoate at 235℃; Product distribution / selectivity;
tin(II) octanoate at 120 - 230℃; Product distribution / selectivity;

L-lactic acid oligomer → L,L-dilactide (4511-42-6)

Conditions	Yield
tin(II) octanoate at 120 - 235℃; Product distribution / selectivity;

Reaxys ID: 11363805 → L,L-dilactide (4511-42-6) + D-lactide (13076-17-0)

Conditions	Yield
tin octanoate at 60 - 300℃; for 0.4h; Product distribution / selectivity; Pyrolysis;

Reaxys ID: 11369849 → L,L-dilactide (4511-42-6) + D-lactide (13076-17-0)

Conditions	Yield
at 60 - 320℃; for 0.433333h; Product distribution / selectivity; Pyrolysis;

(6S)-3-methylene-6-methyl-1,4-dioxane-2,5-dione (1071822-17-7) → (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) + L,L-dilactide (4511-42-6)

Conditions	Yield
With 10% Pd on charcoal; hydrogen In tetrahydrofuran at 20℃; under 21446.5 Torr; for 18h; Autoclave; optical yield given as %de;

(3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) → L,L-dilactide (4511-42-6) + D-lactide (13076-17-0)

Conditions	Yield
Na-ethylhexanoate at 160℃; for 15h; Product distribution / selectivity; Racemisation; Parr reactor;
Multi-step reaction with 2 steps 1: potassium phosphate / ethyl acetate / 168 h / 20 °C 2: 1,8-diazabicyclo[5.4.0]undec-7-ene / toluene / 4 h / 110 °C View Scheme

L-Lactic acid (79-33-4) → (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) + L,L-dilactide (4511-42-6) + D-lactide (13076-17-0)

Conditions	Yield
Stage #1: L-Lactic acid In water at 170℃; under 80 Torr; for 3h; Stage #2: tin catalyst at 220℃; under 10 - 15 Torr; Product distribution / selectivity;
With potassium hydroxide; stannous octoate at 150 - 240℃; under 7.50075 Torr; Product distribution / selectivity;

Ethyl isobutyrate (97-62-1) → L,L-dilactide (4511-42-6)

Conditions	Yield
With Triethylene glycol dimethyl ether; titanium(IV) tetraethanolate at 120℃; for 7.5h; Inert atmosphere;

3,6-dimethyl-1,4-dioxane-2,5-dione → (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) + L,L-dilactide (4511-42-6) + D-lactide (13076-17-0)

Conditions	Yield
With 1,8-diazabicyclo[5.4.0]undec-7-ene In toluene at 110℃; for 4h; optical yield given as %ee;

LACTIC ACID (849585-22-4) → L,L-dilactide (4511-42-6)

Conditions	Yield
Stage #1: LACTIC ACID at 70℃; under 60.006 Torr; Stage #2: With tin(II) phosphite at 70 - 250℃; under 7.50075 - 15.0015 Torr; Pressure;

LACTIC ACID (849585-22-4) → (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) + L,L-dilactide (4511-42-6)

Conditions	Yield
Stage #1: LACTIC ACID at 70℃; under 60.006 Torr; Stage #2: With tin(II) octanoate at 70 - 250℃; under 7.50075 - 15.0015 Torr;

L-Lactic acid (79-33-4) + (R)-2-hydroxylbutanoic acid (20016-85-7) → C7H10O4 + (R)-3,6-diethyl-1,4-dioxane-2,5-dione (1621671-24-6) + L,L-dilactide (4511-42-6)

Conditions	Yield
With H-BEA In o-xylene for 3h; Dean-Stark; Heating;	A 46.5 %Chromat. B 23.8 %Chromat. C 29 %Chromat.

D-lactide (13076-17-0) → (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) + L,L-dilactide (4511-42-6)

Conditions	Yield
With sodium sulfite at 190℃; for 4h; Reagent/catalyst; Temperature; stereoselective reaction;

(S)-Methyl lactate (27871-49-4) → Methyl 2-(2-hydroxypropionyl)propionate (2037-15-2) + (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione (13076-19-2) + L,L-dilactide (4511-42-6)

Conditions	Yield
With TiO2 on amorphous SiO2 at 220 - 300℃; under 760.051 Torr; Catalytic behavior; Reagent/catalyst; Inert atmosphere;

L,L-dilactide (4511-42-6) → poly-L-lactide

Conditions	Yield
With [1,5-dithiapentadiyl-bis(4,6-di-t-Buphenol)Y{N(SiHMe2)2}THF] In toluene at 25℃; for 20h; Product distribution; Further Variations:; Reagents; Solvents;	100%
With Ti[S(4-Me-6-tBu(C6H2O)2](NEt2)2 In toluene at 100℃; for 120h; Product distribution;	90.3%
tin(II) octanoate at 100 - 180℃; for 1h;

L,L-dilactide (4511-42-6) → poly(L-lactide), Mn(GPC) = 6.00E-4, PDI = 2.01; monomer(s): L-lactide

Conditions	Yield
With (TMS)2NYb[Me3SiNC(Ph)N(CH2)3NC(Ph)NSiMe3]2YbN(TMS)2 In toluene at 60℃; for 0.166667h;	100%

L,L-dilactide (4511-42-6) → poly(L-lactide), Mn(GPC) = 4.10E-4, PDI = 1.31; monomer(s): L-lactide

Conditions	Yield
With [Me3SiNC(Ph)N(CH2)3NC(Ph)NSiMe3]Yb[NH(2,6-iPr2C6H3)](DME) In toluene at 60℃; for 0.0166667h;	100%

L,L-dilactide (4511-42-6) → Reaxys ID: 11841898

Conditions	Yield
With N,N'-bis(2,6-diisopropylphenyl)-1,6,7,12-tetra-[4-(2-hydroxyethyl)phenoxy]perylene-3,4,9,10-tetracarboxylic acid diimide; stannous octoate In toluene at 90 - 110℃; for 48h;	100%
C42H90ErO6P3 Product distribution / selectivity;
C28H62MgO4P2(2+)*2Cl(1-) Product distribution / selectivity;

methanol (67-56-1) + L,L-dilactide (4511-42-6) → (S)-Methyl lactate (27871-49-4)

Conditions	Yield
With [Mg(tbpca)2] In dichloromethane at 25℃; for 6h; Inert atmosphere; chemoselective reaction;	99.5%
With Ca[N(SiMe3)2]2*2THF In toluene at 30℃; for 0.166667h;	94%
With [Li6(methyl salicylato)6] at 25℃; for 2.5h; Time; Inert atmosphere; Glovebox;

triphenylmethyl sulfanylethyl alcohol (29167-28-0) + L,L-dilactide (4511-42-6) → polymer (H(O-CH(CH3)-CO)n-O-CH2CH2-S-(trityl)), Mn = 5500(SEC), 5000(NMR), Mw/Mn = 1.3; monomer(s): L-lactide; 2-(tritylsulfanyl)ethan-1-ol

Conditions	Yield
With stannous octoate In 1,4-dioxane at 60℃; for 40h;	99%

triphenylmethyl sulfanylethyl alcohol (29167-28-0) + L,L-dilactide (4511-42-6) → polymer (H(O-CH(CH3)-CO)n-O-CH2CH2-S-(trityl)), Mn = 14600(SEC), 12400(NMR), Mw/Mn = 1.4; monomer(s): L-lactide; 2-(tritylsulfanyl)ethan-1-ol

Conditions	Yield
With stannous octoate In 1,4-dioxane at 60℃; for 40h;	99%

triphenylmethyl sulfanylethyl alcohol (29167-28-0) + L,L-dilactide (4511-42-6) → polymer (-O-CH2CH2-S-(trityl) terminated), Mn = 3000(SEC), 2700(NMR), Mw/Mn = 1.4; monomer(s): L-lactide; 2-(tritylsulfanyl)ethan-1-ol

Conditions	Yield
With stannous octoate In 1,4-dioxane	99%

L,L-dilactide (4511-42-6) + benzyl alcohol (100-51-6) → poly-L-lactide with benzyl ester and hydroxyl end-groups, Mn = 14000, Mw/Mn = 1.37; monomer(s): L-lactide; benzyl alcohol

Conditions	Yield
With 6-[MeOCH2CH2N(Me)CH2]-2,4-(tBu)2-phenolate lithium complex In dichloromethane at 26.5℃; for 0.25h;	98%

ethanol (64-17-5) + L,L-dilactide (4511-42-6) → (S)-2-hydroxy-propionic acid (S)- 1-ethoxycarbonyl-ethyl ester (64231-47-6)

Conditions	Yield
With [Mg(tbpca)2] In dichloromethane at 25℃; for 1h; Inert atmosphere; chemoselective reaction;	98%
With [(1S)-7,7-dimethyl-2-oxobicyclo[2.2.1]hept-1-yl]methanesulfonic acid In toluene at 25 - 80℃; for 2h; Inert atmosphere;	60%
With camphor-10-sulfonic acid In toluene at 25 - 80℃; for 2h;	60%
With camphor-10-sulfonic acid In toluene at 25 - 80℃; for 2h;	60%
Stage #1: ethanol With n-butyllithium In tetrahydrofuran; hexane at -78℃; for 0.0833333h; Stage #2: L,L-dilactide In tetrahydrofuran; hexane for 0.5h;

N-tert-butoxycarbonyl-3-aminopropanol (58885-58-8) + L,L-dilactide (4511-42-6) → boc-aminopropyl-poly(lactic acid)20

Conditions	Yield
Stage #1: L,L-dilactide In toluene at 80℃; for 1h; Stage #2: N-tert-butoxycarbonyl-3-aminopropanol With diethylzinc In toluene at -10 - 20℃; Stage #3: With acetic acid In toluene	98%

N-tert-butoxycarbonyl-3-aminopropanol (58885-58-8) + L,L-dilactide (4511-42-6) → boc-aminopropyl-poly(lactic acid)30

Conditions	Yield
Stage #1: N-tert-butoxycarbonyl-3-aminopropanol With diethylzinc In toluene at -10 - 20℃; for 1h; Stage #2: L,L-dilactide In toluene at 80℃; for 2h; Stage #3: With acetic acid In toluene Product distribution / selectivity;	98%

N-tert-butoxycarbonyl-3-aminopropanol (58885-58-8) + L,L-dilactide (4511-42-6) → boc-aminopropyl-poly(lactic acid)50

Conditions	Yield
Stage #1: N-tert-butoxycarbonyl-3-aminopropanol With diethylzinc In toluene at -10 - 20℃; for 1h; Stage #2: L,L-dilactide In toluene at 80℃; for 2h; Stage #3: With acetic acid In toluene	98%

N-tert-butoxycarbonyl-3-aminopropanol (58885-58-8) + L,L-dilactide (4511-42-6) → boc-aminopropyl-poly(lactic acid)80

Conditions	Yield
Stage #1: L,L-dilactide In toluene at 80℃; for 1h; Stage #2: N-tert-butoxycarbonyl-3-aminopropanol With diethylzinc In toluene at -10 - 20℃; Stage #3: With acetic acid In toluene	98%

C39H47N5O13*ClH + L,L-dilactide (4511-42-6) → C129H167N5O73

Conditions	Yield
Stage #1: C39H47N5O13*ClH With sodium hydroxide In water Stage #2: L,L-dilactide With dmap In N,N-dimethyl-formamide at 55℃;	98%

triphenylmethyl sulfanylethyl alcohol (29167-28-0) + L,L-dilactide (4511-42-6) → polymer (H(O-CH(CH3)-CO)n-O-CH2CH2-S-(trityl)), Mn = 10100(SEC), 8200(NMR), Mw/Mn = 1.3; monomer(s): L-lactide; 2-(tritylsulfanyl)ethan-1-ol

Conditions	Yield
With stannous octoate In 1,4-dioxane at 60℃; for 40h;	97%

methanol (67-56-1) + L,L-dilactide (4511-42-6) → (1-methoxy-1-oxopropane-2-yl)-2-hydroxypropionate

Conditions	Yield
With potassium hexamethylsilazane at 55℃; for 1h;	97%
With [Zn(N-[methyl(2-hydroxy-3,5-di-tert-butylphenyl)]-N-methyl-N-cyclohexylamine(-1H))2] In dichloromethane at 20℃; Reagent/catalyst; Solvent; Temperature; Schlenk technique;
at 25℃; for 241h; Time; Inert atmosphere; Glovebox;

triphenylmethyl sulfanylethyl alcohol (29167-28-0) + L,L-dilactide (4511-42-6) → polymer (H(O-CH(CH3)CO)n-O-CH2CH2-S-(trityl)), Mn = 15300(SEC), 19000(NMR), Mw/Mn = 1.9; monomer(s): L-lactide; 2-(tritylsulfanyl)ethan-1-ol

Conditions	Yield
With stannous octoate In 1,4-dioxane at 60℃; for 40h;	96%

L,L-dilactide (4511-42-6) + benzyl alcohol (100-51-6) → α-H-ω-benzyl-terminated poly[(S)-oxy-1,1-ethanediyl-carbonyl-oxy-1,1-ethanediyl-carbonyl], ring opening polymerization product; monomer(s): L-lactide; benzyl alcohol

Conditions	Yield
With tert-Butoxybis(dimethylamino)methane In tetrahydrofuran at 70℃; for 0.166667h; Product distribution; Further Variations:; Reagents; Pressures; vacuum;	96%

L,L-dilactide (4511-42-6) → poly(lactide), by ring-opening polimerization, Mn (GPC) = 13700, Mw/Mn = 1.06; monomer(s): L-lactide

Conditions	Yield
With benzyl alcohol In toluene at 50℃; for 0.5h;	96%

L,L-dilactide (4511-42-6) → poly(L-lactide), Mn(GPC) = 6.50E-4, PDI = 1.29; monomer(s): L-lactide

Conditions	Yield
With [Me3SiNC(Ph)N(CH2)3NC(Ph)NSiMe3]Yb[NH(2,6-iPr2C6H3)](DME) In toluene at 60℃; for 0.116667h;	95%

L,L-dilactide (4511-42-6) + benzyl alcohol (100-51-6) → poly(L-lactide), benzyl ester at one chain-end, Mn = 10300, Mw/Mn = 1.08

Conditions	Yield
(MeOCH2CH2N-{CH2-[2-LiO-3,5-C6H2(tBu)2]}2)2 In dichloromethane at 26.5℃; for 0.25h;	95%

L,L-dilactide (4511-42-6) + benzyl alcohol (100-51-6) → benzyl (S)-Lactate (56777-24-3)

Conditions	Yield
With Ca[N(SiMe3)2]2*2THF In toluene at 30℃; for 0.0833333h;	95%

L,L-dilactide (4511-42-6) + butan-1-ol (71-36-3) → C124H170O81

Conditions	Yield
With Rasta resin-(1,5,7-triazabicyclo[4.4.0]dec-5-ene)[RR-TBD] In chloroform-d1 at 20℃; for 2h;	95%

Sorbyl alcohol (17102-64-6) + L,L-dilactide (4511-42-6) → polylactic acid

Conditions	Yield
Stage #1: Sorbyl alcohol With n-butyllithium In tetrahydrofuran; hexane at -78℃; for 0.5h; Stage #2: L,L-dilactide In tetrahydrofuran; hexane at -78 - 20℃; Stage #3: With acetic acid In tetrahydrofuran; hexane	94.4%

ethanol (64-17-5) + L,L-dilactide (4511-42-6) + sorbinyl chloride (2614-88-2) → polylactic acid

Conditions	Yield
Stage #1: ethanol With n-butyllithium In tetrahydrofuran; hexane at -78℃; for 0.5h; Stage #2: L,L-dilactide In tetrahydrofuran; hexane at -78 - 20℃; Stage #3: sorbinyl chloride In tetrahydrofuran; hexane at -78℃; for 1h;	94.2%

Upstream product

• 79-33-4 L-Lactic acid 
• 13076-17-0 D-lactide 
• 27871-49-4 (S)-Methyl lactate 
• 20016-85-7 (R)-2-hydroxylbutanoic acid 
• 849585-22-4 LACTIC ACID 
• 661-19-8 1-docosanol 
• 26680-10-4 3,6-dimethyl-1,4-dioxane-2,5-dione 
• 687-47-8 (S)-Ethyl lactate 
• 97-62-1 Ethyl isobutyrate 
• 13076-19-2 (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione 
• 1071822-17-7 (6S)-3-methylene-6-methyl-1,4-dioxane-2,5-dione 
• 2216-51-5 (-)-menthol 
• 547-64-8 methyl lactate 
• 620627-85-2 sec-phenethyl O-lactoyllactate 

Downstream Products

• 27871-49-4 (S)-Methyl lactate 
• 687-47-8 (S)-Ethyl lactate 
• 63697-00-7 (S)-isopropyl lactate 
• 56777-24-3 benzyl (S)-Lactate 
• 34451-19-9 butyl (S)-(-)-lactate 
• 95-96-5 D,L-lactide 
• 13076-19-2 (3R,6S)-3,6-dimethyl-1,4-dioxane-2,5-dione 
• 13076-17-0 D-lactide 
• 314069-33-5 (S)-2-hydroxy-propionic acid (S)-1-benzyloxycarbonyl-ethyl ester 
• 1079277-94-3 C₁₉H₃₀O₅Si 
• 909025-02-1 C₂₂H₃₄O₇Si 
• 909025-03-2 C₂₅H₃₈O₉Si 
• 909025-06-5 C₂₈H₄₂O₁₁Si 
• 909025-08-7 C₃₄H₅₀O₁₅Si 

Relevant articles and documents

SYNTHESIS METHOD AND DEVICE FOR RAPIDLY PRODUCING LACTIDE AT HIGH YIELD

The invention discloses a synthesis method and device for rapidly producing lactide at high yield. The method comprises: adding a single component of lactic acid or two components of lactic acid and catalyst, passing the mixture through a mixer to enter an oligomer preparation system, increasing a residence time through bottom circulation, synthesizing oligomeric lactic acid, and passing a gas-phase component through a rectification system. With the adoption of the device, the lactide is capable of being efficiently synthesized, crude lactide with a yield of 94% to 98% is capable of being obtained.

Method for synthesizing rod-like long L-lactide crystal with high optical purity

The invention discloses a method for synthesizing a rod-like long L-lactide crystal with high optical purity, namely the method for synthesizing the rod-like long L-lactide crystal with the high optical purity by utilizing a decompression method with lactic acid as a raw material. A synthesis technology of the rod-like long L-lactide crystal with the high optical purity comprises the following conditions: the amount of a certain amount of the lactic acid is 10-50mL, the volume of a proper amount of catalyst stannous octoate is 1-10mL, the gradually rising temperature range from 90 to 190 DEG C, and the pressure of a reduced pressure distillation reaction is minus 0.10MPa to 0.10MPa, and a certain time is 1-10h. A synthesis method of the rod-like long L-lactide crystal with the high opticalpurity comprises the following steps: 1), taking a certain amount of the lactic acid, adding into a three-necked bottle of 250mL, then adding a proper amount of stannous octoate, gradually heating, and performing a reduced pressure distillation reaction for a certain time to obtain a white lactic acid oligomer; 2), gradually heating the white lactic acid oligomer in a device, and performing the reduced pressure distillation reaction for a certain time until no obvious distillate appears, and collecting the distillate, that is a lactide product, wherein the product is a mixture of D-type lactide and L-type lactide.

Continuous lactide synthesis process and apparatus

Lock taken bath used for energy intensive processes the synthesis polylactic acid number are disclosed. In the present invention newly developed SnO2 - SiO2 Nano composite catalyst effect using won - based substrate. The catalyst is fast reaction rates (20 ms) and enabling a 94% yield (highest yield temporal) are used to lock taken number tank. Process of the present invention is rapid kinetics and high yield as well as, the commonly used contrast process has numerous advantages. In addition, the fast reaction rates, its processing amount significantly maxims. In addition, the process of the present invention carried out in atmospheric conditions, the high vacuum conditions (20 mmHg) is operated in a more energy efficient during processes currently used are disclosed. Thus, the process of the present invention can reduce costs associated with polylactic acid number tub. (by machine translation)