SIMPLE SYNTHETIC ENTRIES INTO THE TRICYCLO[5.3.1.1(3,9)]DODECANE AND 8-OXATETRACYCLO[5.4.1.1(3,10).0(5,9)]TRIDECANE RING-SYSTEMS

The bis(enolate) of diester 1 undergoes a double intramolecular alkyla tion reaction with 3-chloro-2-chloromethylprop-1-ene 2 to form the tri cyclic product 3 in 75% yield. This conversion represents the first hi gh-yielding route to derivatives of tricyclo[5.3.1.1(3,9)]dodecane, an alicyclic ring system of considerable theoretical and structural inte rest. Diol derivatives 5, 7, 10, 16 and 17 are prepared to investigate further the crystal engineering requirements for obtaining new helica l tubuland hosts. The X-ray structures of 5, 10 and 7 reveal one-, two -and three-dimensional hydrogen bonded lattice structures, respectivel y, despite their remarkable molecular similarity. Solid 5 comprises ch ains assembled through intermolecular ... H-O ... H-O ... H-O ... and novel intramolecular alkene ... H-O hydrogen bonds; while diol 10 form s double layers of diols constructed from recurved spiral chains (four molecules per repeat unit) of intermolecular ... H-O ... H-O ... H-O ... hydrogen bonds. When crystallised from diethyl ether, the hydroxy groups of 7 are linked ... H-O ... H-O ... H-O ... around threefold sc rew axes to give a further example of the helical tubuland lattice. Th is is a microporous solid with empty tubes of cross-sectional area 17. 8 Angstrom(2) parallel to z. Appropriately functionalised tricyclo[5.3 .1.1(3,9)]dodecanes undergo efficient intramolecular cyclisation provi ding compounds 18, 20, 22 and 24 which are the first reported derivati ves of 8-oxatetracyclo[5.4.1.1(3,10).O-5,O-9]tridecane.