1-Propene, 1,1-diethoxy- → n-hexane trans-2,2-diethoxy-3,6-dimethyl-4-ethoxy-N-ethoxycarbonyl-3,4-dihydro-2H-pyran-5-carboxamide

HRID 466274Notes

Reaction equation

[CH2:1]([O:3][C:4]([NH:6][C:7](=[O:16])[C:8](=[CH:12][O:13][CH2:14][CH3:15])[C:9](=[O:11])[CH3:10])=[O:5])[CH3:2].[CH2:17]([O:19][C:20]([O:23][CH2:24][CH3:25])=[CH:21][CH3:22])[CH3:18]>C1(C)C=CC=CC=1>[CH2:17]([O:19][C:20]1([O:23][CH2:24][CH3:25])[C@@H:21]([CH3:22])[C@H:12]([O:13][CH2:14][CH3:15])[C:8]([C:7]([NH:6][C:4]([O:3][CH2:1][CH3:2])=[O:5])=[O:16])=[C:9]([CH3:10])[O:11]1)[CH3:18].[CH3:17][CH2:18][CH2:12][CH2:8][CH2:9][CH3:10]

Participants

Conditions

Temperature: 40 °C

Procedure

N-Ethoxycarbonyl-2-ethoxymethylene-3-oxobutanamide (2.3 g) was dissolved in toluene (15 ml) and treated dropwise with 1,1-di-ethoxyprop-1-ene (2 g). The mixture was stirred at 40° C. for 2 hours and evaporated to dryness. The residual oil was purified by medium pressure liquid chromatography on K60 silica using ethyl acetate/petroleum ether b.p. 60°-80° C. 15/85 v/v and 20/80 v/v as eluting solvents, to give after trituration with n-hexane trans-2,2-diethoxy-3,6-dimethyl-4-ethoxy-N-ethoxycarbonyl-3,4-dihydro-2H-pyran5-carboxamide (0.6 g) m.p. 84°-7° C. The n.m.r. spectrum in deuterochloroform displayed the --CH(OEt)-- signal at 3.9 ppm (doublet of quartets, 1H J=3 Hz and 1 Hz), which is indicative of the trans arrangement of the 3 and 4 substituents.

Workup

customevaporated to dryness
customThe residual oil was purified by medium pressure liquid chromatography on K60 silica
wash15/85 v/v and 20/80 v/v as eluting solvents

Sources & evidence

ORD record: ord-611603555822424e8ee56d4ab7bfccab
Source dataset: uspto-grants-1992_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05155236

Reaction notes

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