| 摘要 |
<p>NEW MATERIAL:An optically active cyclopentene derivative expressed by formula I {A is H or R'CO (R' is lower alkyl); R is H or lower alkyl]/ EXAMPLE:(3R,4R)-tans-4-Acetoxy-3-ethoxycarbonylmethylcyclopentene. USE:Useful as a synthetic intermediate for (1S,5R)-cis-2-oxabicyclo[3.3.0]oct-6-en-3- one which is an useful intermediate for prostaglandins important as medicines. PREPARATION:A compound expressed by formula II is reacted with a lower alkyl orthoacetate in the presence of an acid catalyst, e.g. phenol, etc., at 110-170 deg.C, preferably 120-140 deg.C to afford the aimed compound expressed by formula I. The compound expressed by formula II which is the starting material is readily synthesized by reaction as shown in the reaction formulas.</p> |
