1. Synthesis of Terpenoids. IV. The Use of Kinetic Enolates of some Methyl Ketones For Terpenoid Syntheses
2. Aldehyde1was prepared in about 50% overall yield from diethyl malonate as follows:a: CH2=CH-CN, triton B (diox.); b: H3O+; c: EtOH, H+(C6H6); d: Na (tol.); e: HOCH2CH2OH, H+(C6H6); f: LiAlH4(THF); g: Collins (CH2Cl2). It is a colorless oil: ir (film) v 2700, 1725 and 1100–1030 cm−1; pmr (CCl4, 60 MHz) δ 3.90 (s,OCH2) and 9.57 (broad s,CH=O)
3. Regiospecific aldol condensations of the kinetic lithium enolates of methyl ketones
4. Compound4a, colorless oil; uv (EtOH) γmax228 nm (ε 10000); ir (film) v 1690 and 1655 (enone s-cis and s-trans conformations), 1620 and 1130–920 cm−1pmr (CCl4, 60 MHz) δ 0.90 (d, J = 6 Hz, (CH3)2CH), 3.93 (s,OCH2CH2O), 6.00 (d, J = 16 Hz, CH-CH=CH-CO) and 6.70 (dd, J1= 16 Hz, J2= 6 Hz, CH-CH[dbnd]CH-C[dbnd]O); ms (70 eV, rel. intensity) z/e 252 (4%), 169 (2%), 99 (92%) and 28 (100%). Compound4b, pale yellow oil; uv (EtOH) γmax260 nm (ε 12800); ir (film) v 1675, 1650, 1620, 1600 and 1100–1030 cm−1; pmr (CCl4, 60 MHz) δ 1.97 and 2.15 (2s, (CH3)2C[dbnd]CH), 3.95 (s,OCH2CH2O), 6.07 (d, J = 16 Hz, CH-CH[dbnd]CH-C[dbnd]O), 6.22 (broad s, (CH3)2C[dbnd]CH-C[dbnd]O) and 6.73 (dd, J1= 16 Hz, J2= 6 Hz, CH-CH[dbnd]CH-C[dbnd]O); ms (70 eV, rel. intensity) z/e 250 (2%), 206 (1%), 167 (2%), 99 (100%), 88 (45%) and 28 (85%)
5. Compound5a, colorless oil; ir (film) v 1710 and 1100–920 cm−1; pmr (CCl4, 60 MHz) δ 0.86 (d, J = 6 Hz, CH3-CH), 0.92 (d, J = 6 Hz, (CH3)2CH) and 3.90 (s,OCH2CH2O); ms (70 eV, rel. intensity) z/e 268 (8%), 183 (8%), 99 (100%), 86 (11%) and 69 (6%). Compound5b, colorless oil; uv (EtOH) γmax237 nm (ε 11400); ir (film) v 1695, 1630 and 1100–1030 cm−1; pmr (CCl4, 60 MHz) δ 0.83 (d, J = 6 Hz,CH3-CH), 1.83 and 2.09 (2s, (CH3)2C[dbnd]CH), 3.80 (s,OCH2CH2O) and 5.87 (broad s, C[dbnd]CH-C[dbnd]O)