Lithium borohydride → (8-(4-Chlorophenylsulfonyl)-9-ethyl-1,4-dioxa-8-azaspiro[4.5]decan-7-yl)methanol

HRID 15745Notes

Reaction equation

HRID 15745 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([N:11]2[CH:20]([CH2:21][CH3:22])[CH2:19][C:14]3([O:18][CH2:17][CH2:16][O:15]3)[CH2:13][CH:12]2[C:23](OCC)=[O:24])(=[O:10])=[O:9])=[CH:4][CH:3]=1.[BH4-].[Li+]>C1COCC1>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([N:11]2[CH:20]([CH2:21][CH3:22])[CH2:19][C:14]3([O:18][CH2:17][CH2:16][O:15]3)[CH2:13][CH:12]2[CH2:23][OH:24])(=[O:10])=[O:9])=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 4148881Lithium borohydride2×HCID 59342412Ethyl 8-(4-chlorophenylsulfonyl)-9-ethyl-1,4-dioxa-8-azaspiro[4.5]decane-7-carboxylate

Product 1

HCID 59342380(8-(4-Chlorophenylsulfonyl)-9-ethyl-1,4-dioxa-8-azaspiro[4.5]decan-7-yl)methanolYield 57%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

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.

Workup

  1. customwas consumed
  2. concentrationThe reaction mixture was concentrated under reduced pressure, and equal portions of EtOAc and Rochelle's salt
  3. additionwere added
  4. washThe aqueous layer was washed with several more portions of EtOAc
  5. dry with materialdried with Na2SO4
  6. concentrationconcentrated
  7. customto give 2.44 g of crude oil
  8. customThe material was purified by column chromatography

Sources & evidence

ORD record
ord-6f0364c3f1a245d7aa5fa0b2b583f5d2
Source dataset
uspto-grants-2010_06
Patent number
US07732609B2

Reaction notes

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