Triethylamine → (3S,3aR,5R)-5-[(benzyloxy)methyl]-3-methyl-3,3a,4,5-tetrahydro-7H-pyrano[3,4-c][1,2]oxazole

HRID 1775722Notes

Reaction equation

HRID 1775722 reaction equation
Cl[O-].[Na+].[CH2:4]([O:11][CH2:12][C@H:13]([O:18][CH2:19][CH:20]=[N:21][OH:22])[CH2:14][CH:15]=[CH:16][CH3:17])[C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1.C(N(CC)CC)C>ClCCl>[CH2:4]([O:11][CH2:12][C@@H:13]1[O:18][CH2:19][C:20]2=[N:21][O:22][C@@H:16]([CH3:17])[C@@H:15]2[CH2:14]1)[C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 23665760Sodium HypochloriteHCID 867010832-{[(2R)-1-(benzyloxy)hex-4-en-2-yl]oxy}-N-hydroxyethanimine

Product 1

HCID 86701084(3S,3aR,5R)-5-[(benzyloxy)methyl]-3-methyl-3,3a,4,5-tetrahydro-7H-pyrano[3,4-c][1,2]oxazole

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
25 °C

Procedure

An aqueous solution of sodium hypochlorite (6.15% solution, 6.6 L) was slowly added to a solution of 2-{[(2R)-1-(benzyloxy)hex-4-en-2-yl]oxy}-N-hydroxyethanimine (C12) (660 g, 2.51 mol) and triethylamine (19 g, 0.19 mol) in dichloromethane (6.6 L) at 25° C. After completion of the addition, the reaction mixture was stirred at 25° C. for 30 minutes. The organic layer was washed with water (3×3 L), dried over sodium sulfate, filtered, and concentrated in vacuo. Purification via chromatography on silica gel (Eluent: ethyl acetate in petroleum ether) provided (3S,3aR,5R)-5-[(benzyloxy)methyl]-3-methyl-3,3a,4,5-tetrahydro-7H-pyrano[3,4-c][1,2]oxazole (C13) as a white solid. Yield: 90 g, 0.34 mol, 14%. The indicated relative stereochemistry of compound C13 was assigned based on NOE studies, which revealed interactions of the methine proton on carbon 3a with both the methine proton on carbon 5 and the protons of the methyl group on carbon 3. LCMS m/z 261.9 [M+H+]. 1H NMR (400 MHz, CDCl3) δ 7.24-7.39 (m, 5H), 4.69 (d, J=13.7 Hz, 1H), 4.57 (AB quartet, JAB=12.2 Hz, ΔνAB=13.8 Hz, 2H), 4.13-4.25 (m, 2H), 3.62-3.70 (m, 1H), 3.55 (dd, half of ABX pattern, J=10, 6 Hz, 1H), 3.47 (dd, half of ABX pattern, J=10, 4 Hz, 1H), 2.93 (br ddd, J=11, 11, 7 Hz, 1H), 2.11 (br dd, J=12.6, 6.8 Hz, 1H), 1.45-1.56 (m, 1H), 1.45 (d, J=6.2 Hz, 3H).

Workup

  1. additionAfter completion of the addition
  2. washThe organic layer was washed with water (3×3 L)
  3. dry with materialdried over sodium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customPurification via chromatography on silica gel (Eluent: ethyl acetate in petroleum ether)

Sources & evidence

ORD record
ord-c56e1a4280874314bf62d86546e00fce
Source dataset
uspto-grants-2016_02
Patent number
US09260455B2

Reaction notes

Loading…