The rhodium(I)-catalyzed intramolecular hydroacylation of unsaturated aldehydes has been investigated. Three useful new catalyst systems have been developed. The catalysts are prepared by the addition of 2 equiv of tri-p-tolylphosphine, tri-p-anisylphosphine, or tris(p-dimethylaminophenyl)phosphine to chlorobis(cyclooctene)rhodium(l) in ethylene-saturated methylene chloride. 4,5-Unsaturated aldehydes afford good yields of substituted cyclopentanones. However, alkyl substitution in either the 2 or the 5 position substantially reduces the yield of ketone. Disubstitution in the 2 position gives rise to ethyl ketones instead. This procedure provides a valuable new route to spirocyclic and fused bicyclic ketones, but is not applicable to the synthesis of ketones of ring size other than five. Furthermore, it is tolerant of almost all important organic functionality except amines.

Summary: We describe a method for n.c.a. radioiodination of pyrrolidino tamoxifen (Idoxifene) based on the electrophilic destannylation of tributylstannyl pyrrolidino tamoxifen. The methods of separation using preparative tlc and HPLC give >95% radiochemical purity and > 7 0 % recovery.

Die intramolekulare Hydroacylierung ungesättigter Aldehyde in Gegenwart der Rh(I)‐Katalysatoren (I) wird untersucht.