Bicarbonate Ion → 2768-53-8

Participants

Reaction Conditions

Reaction Steps

To methyl ester 21 (1.64 g, 4.27 mmol) dissolved in 25 mL of THF and cooled to 0° C. was added LiOH.H2O (0.25 g, 140 mol %) dissolved in 8 mL of water. The resulting solution was cooled to 0° C., added to the THF solution of 27, stirred at 0° C. for 0.5 h, then poured into 50 mL of saturated aqueous bicarbonate. The basic mixture was then extracted with 50 mL of ether which was discarded. The water layer was acidified with 1N HCl to pH 2 and extracted with 2×100 mL of ether. The organic extracts were combined, dried, and evaporated to give a thick white foam, which was crystallized from ether/hexane affording 1.53 g, 97% of 11 as a white powder; mp 126°-127° C.; [α]25D +39.8° (c 2.1, CHCl3); 1H NMR δ 11.5-11.1 (br s, 1H), 7.40-7.10 (m, 10H), 6.80 (d, 1H, J=5), 5.49 (d, 1H, J=4), 5.07 (s, 2H), 4.49-4.46 (m, 1H), 4.25-4.23 (m, 1H), 3.18 (dd, 1H, J=14, 5.5), 3.03 (dd, 1H, J=14, 6.5), 1.28 (d, 3H, J=7). Anal. Calcd for C24H22N3O5 : C, 64.8; H, 6.0,; N, 7.6. Found: C, 64.8; H, 6.0; N, 7.4.

Provenance & Evidence