Acetate → HCID 130298492, compound

Participants

Reaction Steps

(±)-cis-4-Acetamidocyclopent-2-enemethyl acetate was hydrolyzed with barium hydroxide as in Example 1. The resulting syrup (acetic acid salt of (±)-4-amino-2-cyclopentene-1-methanol) was converted to free amine by stirring with an excess of Amberlite IRA-400 (OH-) resin in water. The resin was filtered off, washed with water, and the filtrate-wash evaporated to a pale yellow syrup which was dried by evaporation of portions of ethanol. Such a sample of amine (2.26 g, 20.0 mmol) and dibenzoyl-D-tartaric acid (Aldrich, 3.62 g, 10.0 mmol as 99%) were dissolved in hot absolute ethanol (35 mL). Refluxing acetonitrile (ca. 150 mL) was added to the cloud point and the solution was allowed to cool slowly to room temperature. The white needles which formed were recrystallized three times from the same solvent combination to give title compound as white plates (1.07 g, 37%); m.p. 160°-162°; [α]20D +66.9°, [α]20436 +165°, [α]20365 +325° (c=0.28, methanol). X-ray crystallography of this salt allowed the absolute configuration of the cation to be fixed by the known configuration of the D-dibenzoyl tartaric acid dianion. This salt crystallized in the space group C2 with one C6H12NO cation and one-half C18H14O8 dianion as the asymmetric unit.

Provenance & Evidence