N-Hydroxyphthalimide → 2,2-Dimethyl-1,3-dioxan-5-ol

HRID 1793056Notes

Reaction equation

HRID 1793056 reaction equation
[CH3:1][C:2]1([CH3:9])[O:7][CH2:6][CH:5]([OH:8])[CH2:4][O:3]1.[OH:10][N:11]1[C:15](=[O:16])[C:14]2=[CH:17][CH:18]=[CH:19][CH:20]=[C:13]2[C:12]1=[O:21].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C(OCC)=O)=NC(OCC)=O>O1CCCC1>[CH3:1][C:2]1([CH3:9])[O:7][CH2:6][CH:5]([OH:8])[CH2:4][O:3]1.[CH3:1][C:2]1([CH3:9])[O:7][CH2:6][CH:5]([O:10][N:11]2[C:12](=[O:21])[C:13]3[C:14](=[CH:17][CH:18]=[CH:19][CH:20]=3)[C:15]2=[O:16])[CH2:4][O:3]1

Participants

7

Reactant 4

HCID 10665N-HydroxyphthalimideHCID 11776TriphenylphosphineHCID 220568ethyl N-ethoxycarbonyliminocarbamateHCID 110298842,2-Dimethyl-1,3-dioxan-5-ol

Product 2

HCID 110298842,2-Dimethyl-1,3-dioxan-5-olHCID 220256752-(2,2-Dimethyl-[1,3]dioxan-5-yloxy)-isoindole-1,3-dione

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

2,2-Dimethyl-[1,3]dioxan-5-ol was prepared as described previously (Forbes, D. C. et al.; Synthesis, 1998; 6:879–882). 1H NMR (400 MHz; DMSO-d6) δ 4.91 (d, 1H, J=5.1), 3.70–3.75 (m, 2 H), 3.41–3.46 (m, 3 H), 1.30 (s, 3 H), 1.24 (s, 3 H); MS (APCI+)=132.9. To a stirring solution of 2,2-dimethyl-[1,3]dioxan-5-ol (1.50 g, 11.35 mmol), N-hydroxyphthalimide (1.85 g, 11.35 mmol), and triphenylphosphine (2.98 g, 11.35 mmol) in anhydrous tetrahydrofuran (30 mL) at 0° C. was added diethyl azodicarboxylate (2.3 mL, 14.75 mmol). The resultant solution was allowed to warm to room temperature. After stirring for 3 hours, the mixture was concentrated in vacuo and charged with chloroform affording white solids. The solids were filtered off and filtrate was collected and concentrated. The residue was purified via silica column chromatography (4:1 hexanes/ethyl acetate) affording 2-(2,2-dimethyl-[1,3]dioxan-5-yloxy)-isoindole-1,3-dione as clear crystals (1.74 g, 55% over 2 steps): 1H NMR (400 MHz; DMSO-d6) δ 7.83 (s, 4 H), 4.11–4.12 (m, 1 H), 4.04–4.09 (m, 2 H), 3.92–3.96 (m, 2 H), 1.32 (s, 3 H), 1.25 (s, 3 H); MS (APCI+)=278.0.

Workup

  1. custom(Forbes, D. C. et al.; Synthesis, 1998; 6:879–882)
  2. concentrationthe mixture was concentrated in vacuo
  3. additioncharged with chloroform affording white solids
  4. filtrationThe solids were filtered off
  5. customfiltrate was collected
  6. concentrationconcentrated
  7. customThe residue was purified via silica column chromatography (4:1 hexanes/ethyl acetate)

Sources & evidence

ORD record
ord-b473736acb5643f9a894944ec78dad40
Source dataset
uspto-grants-2006_07
Patent number
US07078438B2

Reaction notes

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