Oxalyl chloride → HCID 54483996, compound

HRID 414143Notes

Reaction equation

[CH2:1]([O:8][C:9]1[C:10]([CH3:26])=[C:11]2[C:16](=[C:17]([CH3:20])[C:18]=1[CH3:19])[O:15][C@@:14]([CH2:22][C:23](O)=[O:24])([CH3:21])[CH2:13][CH2:12]2)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(Cl)(=O)C([Cl:30])=O>>[CH2:1]([O:8][C:9]1[C:10]([CH3:26])=[C:11]2[C:16](=[C:17]([CH3:20])[C:18]=1[CH3:19])[O:15][C@@:14]([CH2:22][C:23]([Cl:30])=[O:24])([CH3:21])[CH2:13][CH2:12]2)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

Reactant 2

HCID 65578Oxalyl chloride

HCID 14368744HCID 14368744, compound

Product 1

HCID 54483996HCID 54483996, compoundYield 105%

Procedure

Reaction of 11.8 g (33.3 mmol) of (S)-(6-bezyloxy-2,5,7,8-tetramethylchroman-2-yl)acetic acid with oxalyl chloride according to Cohen et al Helv. Chim. Acta, 1978 61, 837 afforded 13.0 g (105%) of (S)-(6-benzyloxy-2,5,7,8-tetramethylchroman-2-yl)acetyl chloride as a yellow oil. This acid chloride was reacted according to Org. Synth., 1984, 63, 198 with 4.94 g (34.3 mmol) of Meldrum's acid and 6.58 g (6.73 mL, 83.2 mmol) of dry pyridine as described above for the racemic series to afford 16.5 g of crude adduct i.e.(S)-5-[2-[3,4-dihydro-2,5,7,8-tetramethyl-6-phenylmethoxy-2H-1-benzopyran-2-yl]-1-hydroxyethylidene]-2,2-dimethyl-1,3-dioxane-4,6-dione as a brownish foam. Crystallization attempts from several solvents or solvent mixtures failed.

Sources & evidence

ORD record: ord-ded37ca2759544888d00efffcb63d7b2
Source dataset: uspto-grants-1988_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04789750

Reaction notes

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