Ethylene Glycol → Ethyl 8-(4-chlorophenylsulfonyl)-9-ethyl-1,4-dioxa-8-azaspiro[4.5]decane-7-carboxylate

Participants

Reaction Steps

Ethyl 1-(4-chlorophenylsulfonyl)-6-ethyl-4-oxopiperidine-2-carboxylate (109; 5.31 g, 14.2 mmol), TMSCl (5.41 ml, 42.6 mmol), and ethylene glycol (3.96 ml, 71.0 mmol) were added to CH2Cl2 (50 ml) and refluxed under nitrogen for 3 hours. The reaction mixture was concentrated tinder reduced pressure, and taken up in equal portions of EtOAc and water. The aqueous layer was washed with several more portions of EtOAc, dried over Na2SO4, and concentrated to give 5.67 g (96%) of a mixture of cis/trans (4:96) isomers as a clear oil which solidified upon standing. The material was used without further purification.

Provenance & Evidence