The products of photolysis of ethyl diazoacetate in neat 1 were partially separated by flash chromatography. Cyclopropanes 2 and 3 and product 5 were isolated in quite pure form and were identified on the basis of their 1H NMR spectra (300 MHz, CDCl3) and mass spectra.
Spectral data for 2: 1H NMR, d 0.98 (ddd, 1H, J = 9, 7, 4 Hz), 1.07 (dt, 1H, J = 9, 4 Hz), 1.24 (s, 3H), 1.25 (t, 3H), 1.27 (s, 3H), 1.32 (s, 1H), 1.56 (ddd, 1H, J = 9, 7, 4 Hz), 1.64 (dt, 1H, J = 9, 4 Hz), 4.12 (q, 2H); MS, m/e (rel inten) 111 (46), 73 (43), 55 (30), 43 (100).
Spectral data for 3: 1H NMR, d 0.94 (ddd, 1H, J = 5.1, 4.5, 3.0 Hz), 1.12 (ddd, 1H, J = 9.0, 7.5, 5.4 Hz), 1.25 (t, 3H), 1.37 (s, 3H), 1.47 (s, 3H), 2.04 (ddd, 1H, J = 7.8, 5.4, 4.5 Hz), 2.11 (ddd, 1H, J = 8.8, 5.6, 3.2 Hz), 2.16 (s, 1H), 4.13 (dq, 2H); MS, m/e (rel inten) 157 (21), 111 (100), 86 (18), 72 (22), 55(25), 43 (69).
Spectral data for 5: 1H NMR, d 0.87 (t, 3H), 1.27 (t, 3H), 1.63 (s, 3H), 1.72 (s, 3H), 2.45 (m, 2H), 4.23 (m, 3H), 5.17 (t, 3H); MS, m/e (rel inten) 154 (14), 111 (40), 72 (34), 69 (67), 43 (100), 41 (77).
The product of carbene insertion into the O-H bond of the substrate (product 4) and the product of addition of the substrate to ethoxyketene (product 6) were identified by GC and GC/MS comparison with authentic samples.
Spectral data for 4: 1H NMR, d 1.24 (t, 3H), 1.31 (s, 6H), 3.94 (s, 2H), 4.21 (q, 2H), 5.16 (d, 1H), 5.18 (d, 1H), 6.05 (dd, 1H); MS, m/e (rel inten) 157 (28), 85 (16), 69 (100), 59 (19), 41 (73).
Spectral data for 6: 1H NMR, d 1.24 (t, 3H), 1.55 (s, 6H), 3.58 (q, 2H), 3.98 (s, 2H), 5.09 (d, 1H), 5.19 (d, 1H), 6.08 (dd, 1H); MS, m/e (rel inten) 69 (100), 59 (46), 43 (17), 41 (62), 31 (62).