Ammonium Chloride → beta(R)-benzyloxy-alpha(RS)-phenyl-1,4-dioxaspiro[4,5]decane-2(R)-ethanol

HRID 1721134Notes

Reaction equation

[CH2:1]([O:8][C@@H:9]([C@H:12]1[CH2:16][O:15][C:14]2([CH2:21][CH2:20][CH2:19][CH2:18][CH2:17]2)[O:13]1)[CH:10]=[O:11])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:22]1([Mg]Cl)[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1.[Cl-].[NH4+]>C(OCC)C.O1CCCC1>[CH2:1]([O:8][C@@H:9]([C@H:12]1[CH2:16][O:15][C:14]2([CH2:21][CH2:20][CH2:19][CH2:18][CH2:17]2)[O:13]1)[CH:10]([C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)[OH:11])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

Conditions

Temperature: -5 °C

Procedure

A solution of 4.30 g (0.015 mmol) of α(S)-benzyloxy-1,4-dioxaspiro[4,5]decane-2(R)-acetaldehyde in 50 ml of anhydrous diethyl ether was cooled to -8° C. and 15 ml of a 2M solution of phenylmagnesium chloride in tetrahydrofuran were added dropwise over a period of 1 hour. The mixture was stirred at -5° C. for 2 hours, then allowed to warm to room temperature and poured into 50 ml of 10% ammonium chloride solution. The mixture was extracted twice with 100 ml of ethyl acetate each time. The ethyl acetate extracts were dried over anhydrous magnesium sulphate and evaporated. The residue was subjected to flash chromatography on silica gel using 5% methanol in dichloromethane for the elution. There were obtained 2.47 g of β(R)-benzyloxy-α(RS)-phenyl-1,4-dioxaspiro[4,5]decane-2(R)-ethanol in the form of a colourless gum; MS (C.I.): m/e 369 [M+H]+.

Workup

temperatureto warm to room temperature
extractionThe mixture was extracted twice with 100 ml of ethyl acetate each time
dry with materialThe ethyl acetate extracts were dried over anhydrous magnesium sulphate
customevaporated
washThe residue was subjected to flash chromatography on silica gel using 5% methanol in dichloromethane for the elution

Sources & evidence

ORD record: ord-160a06e8d682422997d36957ce5156f7
Source dataset: uspto-grants-1996_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05508430

Reaction notes

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