NEW MATERIAL:The compound of formula I [R is hydroxyl-protecting group; X is H, CO2R' (R is H, 1W7C alkyl or means a salt of CO2H as CO2R') or group of formula II; when X is H, Y is CO2R' or group of formula III; when X is CO2 R' or group of formula II, Y is H].
EXAMPLE: 2S-bicyclo[2,2,1]hept-5-ene-2-endo-carboxylic acid.
USE: A synthetic intermediate for Corey lactone and its optically active isomer which is an intermediate for prostaglandins useful as a medicine such as parturifacient, peripheral blood flow improver, etc.
PREPARATION: The compound of formula I can be produced by asymmetric Diels-Alder reaction of a compound of formula IV with a compound of formula V (D-pantolactone acrylic acid ester) in the presence of an insert solvent and a Lewis acid at -100W0°C.
ARAI KAZUTAKA
OBARA YOSHIO
TAKAHASHI YASUHIRO
TETRAHEDRON LETTERS=1985