摘要:
The A ring which is six-membered in 1 and five-membered in 2 is activated by alkali leading to the transformations 1 --> 3 (Co-C bond formation) and 2 --> 4 (C-S bond cleavage). This specificity has been rationalized in terms of a simple scheme which is extendable to other systems as well. The X-ray structure of the 1:1 chloroform adduct of complex 3 is reported.