1: NaOEt / ethanol 2: (i) aq. KOH, EtOH, (ii) (decarboxylation) View Scheme

2,3,11,12-dicyclohexano-1,4,7,10,13,16-hexaoxacyclo-octadecane 1.) 0-5 deg C, 2.) 12 h, RT; Yield given;

(i) aq. KOH, EtOH, (ii) (decarboxylation); Multistep reaction;

1: borane-dimethyl sulfide 2: 99 percent / triethylamine / CH2Cl2 / 1.) 0-5 deg C, 15 min, 2.) 2 h, 0-5 deg C 3: 93 percent / dicyclohexyl-18-crown-6 ether / acetonitrile / 1.) RT, 4 h, 2.) reflux, 2 h 4: 97.7 percent / KOH / H2O; ethanol / 48 h 5: 75 percent / PPA / 2 h / 100 °C 6: NaBH4 / methanol / 16 h / Ambient temperature 7: 81 percent / 1.) p-toluenesulfonic acid, 2.) chloranil / benzene / 1.) reflux, 2 h, 2.) reflux, 24 h 8: N-bromosuccinimide, benzoyl peroxide / CCl4 / 6 h / Heating 9: 71 percent / 1.) hexamethylenetetramine, 2.) 50percent acetic acid / 1.) chloroform, reflux, 90 min, 2.) reflux, 90 min View Scheme

1: borane-dimethyl sulfide 2: 99 percent / triethylamine / CH2Cl2 / 1.) 0-5 deg C, 15 min, 2.) 2 h, 0-5 deg C 3: 93 percent / dicyclohexyl-18-crown-6 ether / acetonitrile / 1.) RT, 4 h, 2.) reflux, 2 h 4: 97.7 percent / KOH / H2O; ethanol / 48 h 5: 75 percent / PPA / 2 h / 100 °C 6: NaBH4 / methanol / 16 h / Ambient temperature 7: 81 percent / 1.) p-toluenesulfonic acid, 2.) chloranil / benzene / 1.) reflux, 2 h, 2.) reflux, 24 h View Scheme