Table 3. Combined Yields and Product Ratios for the Synthesized Methoxymethylene Piperidines.
| entry | R | starting material | Wittig products (%)a,b,c |
|---|---|---|---|
| 1 | 2S-Me | 2S-2a | 2S-9 + 9′a (90)–Z:E, 1.2:1.0 |
| 2 | 2R-Me | 2R-2′a | 2R-9 + 9′b (75)–Z:E, 1.2:1.0 |
| 3 | 2R-Ph | 2R-2c | 2R-9 + 9′c (97)–Z:E, 1.0:1.0 |
| 4 | 2S-Ph | 2S-2′c | 2S-9 + 9′d (78)–Z:E, 1.1:1.0 |
Reaction conditions: [(Ph3)PCH2OCH3]Cl, LDA, 4 Ȧ MS, THF, −78 °C → rt, 16 h.
Isolated combined yield.
The ratio was determined by analysis of the 1H NMR spectra (entries 1–3) or derived from the isolated product yields (entry 4).
