| 摘要 |
<p>A compound of formula (I) <IMAGE> (I) is prepared by cyclizing a compound of formula (IIa) or (IIb) or a mixture thereof <IMAGE> (IIa) <IMAGE> (IIb) wherein X is hydroxyl or halogen and R1 and R2 independently, represent hydroxy protecting groups) followed by removal of the protecting groups R1 and R2. The compound (I) is of use as an intermediate in the stereoselective preparation of (+/-) trans-5-fluoro-2,3,3a,9a-tetrahydro-1H-[1,4]benzodioxino[2,3-c] pyrrole, which is a selective beta 2-adrenoreceptor antagonist and is thus of potential value, in particular, for the treatment or prevention of depression.</p> |
