To the resulting hemiacetal (1.04 g, 3 mmol), monoester 1 (0.61 g, 3 mmol), EDC (0.74 g, 3 mmol x 1.3 eq.), and catalytic amount of DMAP
were added under nitrogen with C[H.sub.2][Cl.sub.2] (30 mL).
Acryloyl chloride, 2-nitrobenzyl alcohol, N,N-dicyclohexylcarbodiimide (DCC, 99%), and N,N7-dimethylaminopyridine (DMAP
, 98%) were purchased from Aldrich.
Poly(ethylene glycol) methyl ether acrylate (PEGMA, [M.sub.n] = 480g/mol, Aldrich) was passed through basic alumina column to remove the inhibitor Ethyl [alpha]-bromoisobutyrate (EBIB, 98%, Aldrich), 2,3,4,5,6-pentafluorobenzyl chloride (Aldrich 99%), CuCl ([greater than or equal to] 99.99%, Aldrich), CuBr (98%, Aldrich), sodium azide (Na[N.sub.3], Sigma-Aldrich), 2,2-bipyridine (bpy, 99%, Fluka), N, N, N', N", N" -pentamethyldiethylenetriamine (PMDETA, 99%, Aldrich), methanol ([greater than or equal to] 99.9, Aldrich), N, NThicyclohexylcarbodiimide (DCC, 99%, Aldrich), 4-(dimethylamino) pyridine (DMAP
, [greater than or equal to] 99.99%, Aldrich), propiolic acid (99%, Aldrich), and N, N-dimethylformamide (DMF, 99%, Aldrich) were used as received.