Multi-step reaction with 12 steps
1: pyridine; DMAP / 0.33 h / 20 °C
2: BF3*Et2O / CH2Cl2 / 0.33 h / 20 °C
3: K2CO3 / methanol / 2 h / 20 °C
4: pyridine / CH2Cl2 / 1 h
5: 18-crown-6 / dimethylformamide / 4 h
6: LiOH / methanol
7: Et3N / CH2Cl2 / 0.33 h / -78 °C
8: mCPBA / CH2Cl2 / -42 °C
9: 21 percent / 2,6-di-tert-butyl-4-methylpyridine; 4 Angstroem molecular sieves; triflic anhydride / toluene; CH2Cl2 / 0.25 h / -78 °C
10: 95 percent / pyridinium hydrofluoride / tetrahydrofuran
11: 74 percent / triflic anhydride; 4 Angstroem molecular sieves / CH2Cl2; diethyl ether / 0.25 h / -78 °C
12: 90 percent / pyridinium hydrofluoride / tetrahydrofuran / 1 h
With
pyridine; dmap; lithium hydroxide; 2,6-di-tert-butyl-4-methylpyridine; 18-crown-6 ether; trifluoromethylsulfonic anhydride; 4 A molecular sieve; boron trifluoride diethyl etherate; potassium carbonate; pyridine hydrogenfluoride; triethylamine; 3-chloro-benzenecarboperoxoic acid;
In
tetrahydrofuran; methanol; diethyl ether; dichloromethane; N,N-dimethyl-formamide; toluene;
1: Acetylation / 2: Substitution / 3: Hydrolysis / 4: sulphonation / 5: Esterification / 6: Hydrolysis / 7: silylation / 8: Oxidation / 9: Condensation / 10: desilylation / 11: Condensation / 12: desilylation;
DOI:10.1021/ja992513f