Bicyclo- -heptene-5-carboxylic

The [2 -I- 2] cycloaddition reaction of l-(trimethylsilyloxy)cyclopentene (63) and acet-ylenecarboxylate, in the presence of ZrCU, was accompanied with desilylation to afford bicyclo[3.2.0]heptene carboxylate 64 (Eq. 27) [28],... 

Maleic anhydride Vinylene carbonate, 2.3-Dihydrofuran, 1-Cyclopenten-3-one Endo-cis-bicyclo[2.2.1] -5-heptene-2.3-dicarboxylic anhydride Citraconic anhydride Cyclobutene-3.4-di-carboxylic anhydride ArCr(CO)3 12) CpMn(CO)3 225) Fe(CO)5 3oo.39 ) CpMn(CO)3 225) ArCr(CO)3 12) CpMn(CO)3 15.225) ArCr(CO)3 12) Fe(CO)5 202,285)... 

Besides of ethene also other alkenes react with carbon dioxide in the presence of nickel(0) complexes. Some examples are given in Figure 6. Hexenes lead to different isomeric heptanoic acids, styrene reacts to cynnamic acid and norbornene (bicyclo 2.2.1 heptene) gives the exo-norbornane-2-carboxylic acid in 95 % yield [5,12,13]. Nor-bornadiene which contains two isolated double bonds reacts to a monoaddition product whose decomposition with hydrochloric acid yields a mixture of six chloronorbornanecarboxylic acids with the chloro-and carboxy-substituents both in exo- and in endo-positions [14]. 

Bicyclo-(2.2.1)- heptene Bicyclo-(2.2.1)- heptane-2 carboxylic acid 80 [489]... 

The second sequence Involves the preparation of from a bicyclo[2,2,l]-heptene intermediate.36 Addition of the carboxyl sidechain in the usual fashion followed by Collins oxidation of the resulting 9-hydroxy-PGA2... 

---