3,4-dihydro-2H-pyran → 8-(tetrahydro-pyran-2-yloxymethyl)-3,4-dihydro-2H-naphthalen-1-one

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Reaction Steps

The diol (Intermediate H3) (2.42 g, 13.5 mmol) was dissolved in CH2Cl2 (75 mL) and reacted with dihydropyran (1.3 mL, 13.8 mmol) and pyridinium para-toluene sulfonate (PPTS) (350 mg, 1.36 mmol) at rt for 18 h. The mixture was concentrated onto SiO2 and purified by chromatography with 10% EtOAc:Hx. The tetrahydropyranyl (THP) protected alcohol (2.02 g, 7.70 mmol) was dissolved in CH2Cl2 (10 mL) and added to a mixture of pyridinium chlorochromate (PCC) (4.9 g, 22.2 mmol), sodium acetate (310 mg, 3.56 mmol) and celite (110 g) in CH2Cl2 (100 mL). The mixture was reacted at rt for 18 h and filtered through celite. The residue was purified by chromatography on SiO2 with 20 to 30% EtOAc:Hx to yield 8-(tetrahydro-pyran-2-yloxymethyl)-3,4-dihydro-2H-naphthalen-1-one (Intermediate H4) (˜55%).

Provenance & Evidence