p-Toluenesulfonic acid → HCID 20365010, compound
Reaction equation
[CH2:1]([O:8][CH:9]([CH2:12][OH:13])[CH2:10][OH:11])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.CO[CH:16](OC)[CH2:17][Cl:18].C1(C)C=CC(S(O)(=O)=O)=CC=1>>[CH2:1]([O:8][CH:9]1[CH2:10][O:11][CH:16]([CH2:17][Cl:18])[O:13][CH2:12]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1Participants
Procedure
A mixture of 5.0 g of 2-benzyloxy-1,3-propanediol, 3.5 g of chloroacetaldehyde dimethyl acetal and 0.3 g of p-toluenesulfonic acid was heated via oil bath through the temperature range 25° to 130° C in a three-necked, round-bottomed flask equipped with stirrer, thermometer and condenser. The by-product methanol, removed by distillation during the course of reaction, amounted to 63% of theory. The reaction mixture was cooled to room temperature and dissolved in ether. The ether solution was washed with 10% sodium carbonate and then with water. After drying over anhydrous sodium sulfate, the ether was removed under reduced pressure. Distillation of the crude oil gave 3.3 g of 5-benzyloxy-2-chloromethyl-1,3-dioxane; b.p. 100°-105° C/0.025 mm Hg; nD25 1.5228. The nmr spectrum was consistent with the assigned structure and showed the cis isomer content to be 30 ± 5%, the remainder being the trans isomer.
Workup
- temperaturewas heated via oil bath through the temperature
- customrange 25° to 130° C
- customequipped with stirrer
- customThe by-product methanol, removed by distillation during the course of reaction
- dissolutiondissolved in ether
- washThe ether solution was washed with 10% sodium carbonate
- dry with materialAfter drying over anhydrous sodium sulfate
- customthe ether was removed under reduced pressure
- distillationDistillation of the crude oil
Sources & evidence
- ORD record
- ord-83cfd3bf191f4de9a3f8a9660cbd40f6
- Source dataset
- uspto-grants-1978_03
- Patent number
- US04077982
Reaction notes
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