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2-ramification of methyl alkyl diol in optical purity

A technology of methyl alkyl diols and derivatives, which is applied in the directions of organic chemistry, chemical instruments and methods, and compounds of elements of Group 4/14 of the periodic table, etc. question

Inactive Publication Date: 2005-08-31
SHANGHAI INST OF ORGANIC CHEMISTRY - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the obtained lactone is not stable in nature, which is not conducive to use and storage

Method used

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  • 2-ramification of methyl alkyl diol in optical purity
  • 2-ramification of methyl alkyl diol in optical purity
  • 2-ramification of methyl alkyl diol in optical purity

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0107]

[0108] R 1 = H, R 2 = Me or R 1 = Me,R 2 =H, n=1 or 2, PG is a hydroxyl protecting group

[0109] 2R-5-tert-butyldimethylsilyloxy-2-methyl-1-pentanol:

[0110] At room temperature, 11.4 grams of 4R-4-methyl-valerolactone as a raw material was dissolved in 100 ml of anhydrous tetrahydrofuran, and 8 grams of LiAlH 4 200ml of anhydrous tetrahydrofuran suspension, after the reaction is complete. The reaction was extracted with ethyl acetate, then water was added dropwise until the solid was white, the white solid was removed by filtration, the residue was fully washed with tetrahydrofuran, the solvent was spinned off under reduced pressure, and then distilled under reduced pressure to obtain 2R-2-methyl-1,5 - 10.8 grams of pentanediol (80°C / 0.1mmHg, 92%)

[0111] 1.2 g of 2R-2-methyl-1,5-pentanediol was dissolved in 10 ml of N, N-dimethylformamide, 1.5 equivalents of imidazole and 1.2 equivalents of TBDMSCl were added, stirred at room temperature for 10 ...

Embodiment 2

[0134]

[0135] R 1 = H, R 2 = Me or R 1 = Me,R 2 =H, n=0 or 1, PG is a hydroxyl protecting group

[0136] 4R-5-methoxymethoxy-4-methyl-1-pentanol:

[0137] At room temperature, 11.4 g of the raw material 4R-4-methyl-valerolactone was dissolved in 100 ml of anhydrous methanol, 0.8 mL of concentrated sulfuric acid was added, and refluxed for 2 hours, after the reaction was completed. Extract with ether, saturated NaHCO 3 Solution washing, water washing, MgSO 4 After drying, the solvent was spin-dried under reduced pressure at low temperature to obtain 14.4 g (99%) of 4R-4-methyl-5-hydroxy-valeric acid methyl ester. 1.4 g of 4R-4-methyl-5-hydroxy-pentanoic acid methyl ester was dissolved in 10 ml of dichloromethane, and 1.5 equivalents of DBU (1,8-diazabicyclo[5,4,0]undec-7-ene) was added , 1.2 equivalents of chloromethoxymethane, stirred at room temperature for 5 hours, the product was extracted with dichloromethane, washed twice with water, MgSO 4 dry. Spin in...

Embodiment 3

[0156]

[0157] R 1 = H, R 2 = Me or R 1 = Me,R 2 =H, n=1 or 2, Y=halogen

[0158] 4R-5-bromo-1-methoxymethoxy-4-methylpentane:

[0159] 19 g of 4R-5-methoxymethyl-4-methyl-1-pentanol was dissolved in 100 mL of dichloromethane, and 1.5 unit volume of PPh was added 3 and 1.5 single quantities of CBr 4 , stirred at room temperature for 4 hours, the product was washed with saturated sodium bicarbonate solution, washed twice with water, MgSO 4 Dry and spin off the solvent. Distillation under reduced pressure at 40°C / 0.2 mmHg yielded 21.2 g of a colorless oil. Yield 95%.

[0160] C8H17BrO2: (225.12)

[0161] Elemental analysis: C%=42.13; H%=7.65; Mass spectrum: (M + , 224)

[0162] 1 H-NMR (CDCl 3 ): δ4.64(s, 2H), 3.4(m, 4H), 3.36(s, 3H), 1.59(m, 5H), 0.95(d, J=6Hz, 3H)

[0163] Made in a similar way:

[0164] 3R-4-bromo-1-methoxymethoxy-3-methylbutane: yield 94%, mass spectrum: (M + ,210);

[0165] 3R-4-bromo-1-ethoxymethoxy-3-methylbutane: yield 92%, m...

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Abstract

An optical-purity 2-methylalkyldiol as a synthetic chiral building block is prepared from 4R-4-methyl valerolactone, 3R-3-methyl butyrolactone, 4S-4-methyl-valerolactone, or 3S-3-methyl butyrolactone. Its preparing process is also disclosed.

Description

technical field [0001] This patent relates to optically pure 2-methyl alkyl diol derivatives, which can be optically pure 2-methyl-1,5-pentanediol (2R-2-methyl-1,5-pentanediol or 2S-2-methyl-1,5-pentanediol), optically pure 2-methyl-1,4-butanediol (2R-2-methyl-1,4-butanediol and 2S-2-methanol -1,4-butanediol) derivatives, etc. They can be conveniently prepared in large quantities by using 4R-4-methylvalerolactone, 4S-4-methylvalerolactone, 3R-3-methylbutyrolactone and 3S-3-methylbutyrolactone respectively as raw materials. Such compounds are very useful building blocks for chiral synthesis. Background technique [0002] Chiral synthetic building blocks characterized by bifunctional structures with chiral methyl side chains, X(CH 2 )mCHCH 3 (CH 2 )nY, has a wide range of uses in organic synthesis. These chiral synthetic building blocks can be used for the synthesis of chiral drugs such as vitamin E and vitamin K, and can be used for the synthesis of insect sex pheromone...

Claims

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Application Information

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IPC IPC(8): C07C31/34C07C43/13C07C43/178C07C47/198C07C69/675C07C69/84C07C317/16C07C323/19C07D307/08C07D317/18C07D339/06C07F7/18
Inventor 田伟生丁凯汪昀
Owner SHANGHAI INST OF ORGANIC CHEMISTRY - CHINESE ACAD OF SCI
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