Selective intermolecular photo-[4+4]-cycloaddition with 8-pyridone mixtures. 3. Synthetic transformations of the trans cross-product (1 alpha,2 beta,5 beta,6 alpha)-3-butyl-9-methoxy-3,7-diazatricyclo[4.2.2.2(2,5)]dodeca-9,11-diene-4,8-dione

Transformations of the tricyclic product 3 derived from [4 + 4] photocycloa ddition of N-butyl-2-pyridone with 4-methoxy-2-pyridone has demonstrated, f or the first time, facile opening of the secondary lactam after activation of the amide nitrogen with a tert-butyl carboxylate (Boc) group. Methanolys is and lithium borohydride reduction both result in opening of the amide gr oup under very mild conditions to give 21 and 24, respectively. Concomitant reduction of a ketone derived from hydrolysis of the enol ether sets an ad ditional stereogenic center in 24 with complete stereogenic control. These reactions illustrate the synthetic potential of the 2-pyridone photocycload dition products, generating a cyclooctene as a single isomer, with function ality at seven carbons and five stereogenic centers.