Lithium Chloride → (S)-3-chloromethyl-1,1,4,4,6-pentamethyl-1,2,3,4-tetrahydronaphthalene

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Reaction Steps

To a solution of (R)-3-carboxymethyl1,1,4,4,6-pentamethyl-1,2,3,4-tetrahydronaphthalene ([α]546 -23.8° (C=1 in benzene)) (2.00 g; 7.69 mmol) in benzene (30 ml), lead tetraacetate (4.00 g; 9.02 mmol) and anhydrous lithium chloride (0.80 g; 18.9 mmol) were added, and the resultant mixture was refluxed for 6 hours. The reaction mixture was washed with water, dilute hydrochloric acid and 6% ammonia water in order. The benzene layer was dried, concentrated and purified on column chromatography to give (S)-3-chloromethyl-1,1,4,4,6-pentamethyl-1,2,3,4-tetrahydronaphthalene (1.22 g; 4.87 mmol). From the ammonia water layer, there was recovered the unreacted carboxylic acid (0.35 g; 1.34 mmol). The yield was 77% (based on the consumed carboxylic acid). [α]546 +26.1° (C=1 in n-hexane).

Provenance & Evidence