反応 #44023

反応方程式

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

収率 57.0%

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

収率 57.0%

溶媒

THF

反応条件

後処理

1. 1
   その他was consumed
2. 2
   濃縮The reaction mixture was concentrated under reduced pressure, and equal portions of EtOAc and Rochelle's salt
3. 3
   workup.ADDITIONwere added
4. 4
   洗浄The aqueous layer was washed with several more portions of EtOAc
5. 5
   乾燥dried with Na2SO4
6. 6
   濃縮concentrated
7. 7
   その他to give 2.44 g of crude oil
8. 8
   その他The material was purified by column chromatography

実験手順

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.

出典