Valacyclovir intermediate
The natural isomer of the abscission-accelerating plant hormone
ChEBI: The naturally occurring (1'S)-(+) enantiomer of abscisic acid. It is an important sesquiterpenoid plant hormone which acts as a regulator of plant responses to environmental stresses such as drought and cold.
Plant hormone and growth regulator that is involved in several physiological mechanisms including seed dormancy, leaf abscission, stomatal movement, and plant stress responses. Through complex interactions with several intracellular signaling systems, it can regulate the expression of hundreds of plant genes.
Crystallise the acid from CCl4/pet ether, EtOH/hexane and sublime it at 120o. Also purify it by dissolving ~30g in 30mL of EtOAc, adding 100mL of hexane and allow to crystallise overnight (yield 8.4g), m 156-158o, 161-163o, [] D +426o (c 0.005M H2SO4 in MeOH). [Cornforth et al. Nature (London) 206 715 1965, Soukemp et al. Helv Chim Acta 72 361 1989.] The RS-isomer was purified on a Kieselgel F254 plate with toluene/EtOAc/AcOH (50:50:3) and has m 188-190o [Cornforth et al. Aust J Chem 45 179 1992]. [Beilstein 17/3 V 13.]
