Application of t-2-benzoyl-t-5-phenylcyclohexane-r-1-carboxylic acid for the preparation of saturated isoindole-fused heterocyclesDedicated to Professor András Messmer on the occasion of his 80th birthday.

t-2-Benzoyl-t-5-phenylcyclohexane-r-1-carboxylic acid 1 reacts with cis-2-aminocyclohexanemethanol to give the saturated cis-isoindolo[2,1-a][3,1]benzoxazine 2. Reaction of 1 with trans-2-aminocyclohex-4-enemethanol yields three diastereomeric isoindolo derivatives 3a-c. Cyclization of 1 with 1,3-diaminopropane results in a diastereomeric mixture of cis-pyrimido[1,2-a]isoindolones 4a,b. With di-endo-norbornane aminoalcohol, 1 reacts to yield a mixture of cis- and trans-annelated diastereomers 5 and 6. In its reactions with di-exo-norbornane and norbornene aminoalcohols, 1 isomerizes to give cis- condensed isoindolo derivatives 7-10. After isolation, the structures were established by (1)H and (13)C NMR spectroscopy, with up-to-date measuring techniques such as NOEDIF, DEPT, HMQC, 2D-NOESY, 2D-COSY and HMBC and, for 10, X- ray measurements. The results show that, with two exceptions, the trans acid 1 undergoes isomerization to give cis-condensed products.