2-[tert-butyl(diphenyl)silyl]ethanol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 6-benzyloxy-4-hydroxy-2-oxo-2H-thiochromene-3-carboxylic acid methyl ester (Compound 62 (h), 591 mg, 1.73 mmol) and 2-(tert-Butyl-diphenyl-silanyl)-ethanol (687 mg, 2.42 mmol) (prepared according to the procedure published in J. Org. Chem. 2005, 70(4), 1467-1470) in THF (7 mL) was added triphenylphosphine (634 mg, 2.42 mmol), and DIAD (489 mg, 2.42 mmol). The resultant mixture was stirred at rt for 3.5 h. After concentration, the crude residue was purified by silica gel chromatography (eluting with 0-75% EtOAc/hexanes) to provide the title compound (697 mg). 1H NMR (200 MHz, CDCl3): δ (ppm)=7.69-7.14 (m, 18H), 5.83 (s, 2H), 4.25-4.09 (m, 2H), 3.49 (s, 3H), 1.89-1.81 (m, 2H), 1.08 (s, 9H). prepared After concentration the crude residue was purified by silica gel chromatography (eluting with 0-75% EtOAc/hexanes)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 6-benzyloxy-4-hydroxy-2-oxo-2H-thiochromene-3-carboxylic acid methyl ester (Compound 62 (h), 591 mg, 1.73 mmol) and 2-(tert-Butyl-diphenyl-silanyl)-ethanol (687 mg, 2.42 mmol) (prepared according to the procedure published in J. Org. Chem. 2005, 70(4), 1467-1470) in THF (7 mL) was added triphenylphosphine (634 mg, 2.42 mmol), and DIAD (489 mg, 2.42 mmol). The resultant mixture was stirred at rt for 3.5 h. After concentration, the crude residue was purified by silica gel chromatography (eluting with 0-75% EtOAc/hexanes) to provide the title compound (697 mg). 1H NMR (200 MHz, CDCl3): δ (ppm)=7.69-7.14 (m, 18H), 5.83 (s, 2H), 4.25-4.09 (m, 2H), 3.49 (s, 3H), 1.89-1.81 (m, 2H), 1.08 (s, 9H). prepared After concentration the crude residue was purified by silica gel chromatography (eluting with 0-75% EtOAc/hexanes)