The photocyclo-adducts 36, obtained by photocycloaddition of terpinolene with methyl 2, 3-dioxo-pentanoate, was subjected to retro- aldol rearrangement to give the substituted-cyclohexene 7 and 12. In acidic or basic condition the recyclization of the open-ring products was carried out. In different reaction media the spirocyclic compounds were obtained by intramolecular Claisen condensation. Using TsOH as a catalyst for cyclization the nucleophilic ene-addition of 7 and 12 generated bicyclo [3.3.1] nonene 9～11 and bicyclo [3.2.1] octane 16～ 18 besides forming spirocyclic compounds. The reaction mechanisms were discussed and the structures of all compounds were assigned based on the data from IR, ~1H NMR and ~(13)C NMR and elemental analysis.

Key words: CYCLOADDITION REACTION;CONDENSATION REACTION;NUCLEOPHILIC REACTION, SPIRO COMPOUNDS;IR;1HNMR;C13NMR