Pivalic acid → ethyl (S)(E)-2-{2-[2-(4-t-butyldimethylsilyloxy-1,3-dihydro-6-ethyl-7-methyl-3-oxoisobenzofuran-5-yl)ethylidene]cyclopent-1-yl}acetate

HRID 1735436

Reaktionsgleichung

Reaktionsgleichung von HRID 1735436
[Si:1]([O:8][C:9]1[C:17]([CH2:18][C@@H:19]([C:21]2[CH2:25][CH2:24][CH2:23][CH:22]=2)O)=[C:16]([CH2:26][CH3:27])[C:15]([CH3:28])=[C:14]2[C:10]=1[C:11](=[O:29])[O:12][CH2:13]2)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].C(O)(=O)C(C)(C)C.[C:37](OCC)([O:42]CC)([O:39][CH2:40][CH3:41])[CH3:38]>>[Si:1]([O:8][C:9]1[C:17]([CH2:18]/[CH:19]=[C:21]2/[C@H:22]([CH2:38][C:37]([O:39][CH2:40][CH3:41])=[O:42])[CH2:23][CH2:24][CH2:25]/2)=[C:16]([CH2:26][CH3:27])[C:15]([CH3:28])=[C:14]2[C:10]=1[C:11](=[O:29])[O:12][CH2:13]2)([C:4]([CH3:5])([CH3:6])[CH3:7])([CH3:2])[CH3:3]

Komponenten

4

Reaktionsbedingungen

Temperatur
138 °C

Versuchsvorschrift

A mixture of (S)-2-(4-t-butyldimethylsilyloxy-1,3-dihydro-6-ethyl-7-methyl-3-oxoisobenzofuran-5-yl)-1-cyclopentenyl-1-hydroxyethane (2.8 g), pivalic acid (0.1 g) and triethyl orthoacetate (125 ml) was heated to 138° C. After 2.5 hours, more pivalic acid (65 mg) was added and the reaction was continued 1 hour more. The reaction mixture was cooled, the excess triethyl orthoacetate removed in vacuo, and the residue chromatographed on silica gel (20% ethyl acetate/hexane) to give ethyl (S)(E)-2-{2-[2-(4-t-butyldimethylsilyloxy-1,3-dihydro-6-ethyl-7-methyl-3-oxoisobenzofuran-5-yl)ethylidene]cyclopent-1-yl}acetate.

Aufarbeitung

  1. waitthe reaction was continued 1 hour
  2. temperatureThe reaction mixture was cooled
  3. customthe excess triethyl orthoacetate removed in vacuo
  4. customthe residue chromatographed on silica gel (20% ethyl acetate/hexane)

Quellen und Nachweise

ORD-Eintrag
ord-79729128720241c6afee2cc19b23a362
Quelldatensatz
uspto-grants-1996_07
Patentnummer
US05536747

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