Reaction #44023

Reaction equation

lithium borohydride

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

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

lithium borohydride

→

mixture

Yield 57.0%

(8-(4-chlorophenylsulfonyl)-9-ethyl-1,4-dioxa-8-azaspiro[4.5]decan-7-yl)methanol

Yield 57.0%

Solvents

THF

Conditions

Workup

1. 1
   Otherwas consumed
2. 2
   ConcentrationThe reaction mixture was concentrated under reduced pressure, and equal portions of EtOAc and Rochelle's salt
3. 3
   workup.ADDITIONwere added
4. 4
   WashThe aqueous layer was washed with several more portions of EtOAc
5. 5
   Dryingdried with Na2SO4
6. 6
   Concentrationconcentrated
7. 7
   Otherto give 2.44 g of crude oil
8. 8
   OtherThe material was purified by column chromatography

Procedure

Ethyl 8-(4-chlorophenylsulfonyl)-9-ethyl-1,4-dioxa-8-azaspiro[4.5]decane-7-carboxylate (110; 2.47 g, 5.92 mmol) and lithium borohydride (4.7 ml, 2.0 M in THF, 9.48 mmol) were added to THF (15 ml). The mixture was stirred for 18 hours under nitrogen at rt which led to only a 25% conversion to the desired alcohol. Solid lithium borohydride was added in equivalent portions and the reaction monitored until the starting ester was consumed. The reaction mixture was concentrated under reduced pressure, and equal portions of EtOAc and Rochelle's salt were added. The aqueous layer was washed with several more portions of EtOAc, dried with Na2SO4, and concentrated to give 2.44 g of crude oil. The material was purified by column chromatography using EtOAc/hexanes gradients to yield 1.26 g (57%) of a mixture of cis/trans isomers.

Source