1: 1.) lithium diisopropylamide / 1.) -78 deg C, 2.) -78 deg C to RT 2: 1.) OH(-), 2.) H(+) 3: Et3N, DCC, HOBT / CH2Cl2 View Scheme

1: 1.) OH(-), 2.) H(+) 2: Et3N, DCC, HOBT / CH2Cl2 View Scheme

benzotriazol-1-ol; triethylamine; dicyclohexyl-carbodiimide in dichloromethane

1.1: N'-(3-dimethylaminopropyl)-N-ethylcarbodiimide / dichloromethane / 0.33 h / 20 °C / Inert atmosphere 1.2: 20 °C / Inert atmosphere 2.1: water; trifluoroacetic acid / 20 °C / Inert atmosphere View Scheme

1.1: 5 h / Inert atmosphere; Reflux 2.1: toluene-4-sulfonic acid; trimethyl orthoformate / 5 h / 20 °C / Inert atmosphere 3.1: water; sodium hydroxide / 20 °C 4.1: N'-(3-dimethylaminopropyl)-N-ethylcarbodiimide / dichloromethane / 0.33 h / 20 °C / Inert atmosphere 4.2: 20 °C / Inert atmosphere 5.1: water; trifluoroacetic acid / 20 °C / Inert atmosphere View Scheme

Multistep reaction;