Ammonium Chloride → (S)-3,4-dihydro-2,5,7,8-tetramethyl-2-vinyl-2H-[1]-benzopyran-6-ol

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Reaction Steps

A solution of 106 mg (0.36 mmol) of (E)-5-(2,5-dihydroxy-3,4,6-trimethylphenyl)-3-methyl-2-pentenyl acetate and 9 mg (3%) of [[(R)-6,6'-dimethyl-1,1'-biphenyl-2,2'-bis(diphenylphosphine)]-P,P'][(η-3)-2-propenyl]palladium perchlorate in 2 ml of DMSO was treated with 15 mg of calcium hydride and stirred at room temperature for three days. Thereafter, the mixture was poured into saturated ammonium chloride solution and extracted with ether. The combined extracts were washed with water and dried. The residue remaining after removal of the solvent was purified as described in Experiment 1, yielding 56 mg of (S)-3,4-dihydro-2,5,7,8-tetramethyl-2-vinyl-2H-[1]-benzopyran-6-ol. O.P. 33%.

Provenance & Evidence