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KlementineJBS / USYD_PhD_ELN

This repository forms the electronic laboratory notebook (ELN)for Klementine Burrell-Sander's PhD's
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KBS35-3 - Formation of propanoate intermediate (1.5 g scale) #136

Closed KlementineJBS closed 9 months ago

KlementineJBS commented 1 year ago

Link to HIRAC.

Previous attempt is #129

Reaction scheme

KBS35 - Formation of propanoate intermediary

Outcome

898.9 mg (3.70 mmol, 46%)

KlementineJBS commented 1 year ago

22.08.23

  1. Dissolved SM (1.5143 g, 8.09 mmol) in ethyl acetate (30 mL)
  2. Added KOtBu (911.1 mg, 8.09 mmol). Took an aliquot at 1 minute.
  3. Left stirring at rt, took an aliquot at 25 min.
  4. Added extra KOtBu (186 mg) at ~30 mins (to make a total of 1.097 g, 9.78 mmol, 1.2 equiv.)
  5. Took an aliquot at 45 min and stopped stirring.

TLC indicated formation of multiple spots, as in previous attempts.

Two new spots appear, with the higher spot being present in the 25 and 45 minute aliquots but not the 1 minute aliquot. Hence, the 1 m aliquot was dissolved in water (1 mL) and extracted with ethyl acetate (2 x 2 mL), then rotovapped and NMR'd.

  1. Added water (~ 100 mL) and extracted with ethyl acetate (3 x 100 mL)
  2. Washed with brine (125 mL) and dried over mag sulphate before rotovapping

Crude mass: 1.7154 g

KlementineJBS commented 1 year ago

H NMR

Compared crude NMR, mystery spot NMR and NMR of purified product from #113. Interestingly, we can see a small amount of product present in the mystery spot NMR - indicating that the reaction is very rapid. Mystery spot resembles but doesn't exactly match NMR of "fractions C" from KBS35-1. Should check second product isolated from #129 and compared.

KBS35-3 cr_1.zip KBS35-3 mystery spot_1.zip KBS35-3 cr.pdf

KlementineJBS commented 1 year ago

Column conditions

W1 and F2-7 were rotovapped down.

Vial: 15.7319 Full vial: 16.6308 Mass: 898.9 mg (3.70 mmol, 46%)