Synthetic approaches to molecules with sterically hidden functional groups. 2. Bicyclo[8.8.2]eicosa-1(19),10(20),19-triene: the first bicyclic cumulatriene

Butatriene-Based Polymer Chemistry. 2. Synthesis and Characterization of Poly[1,1,4,4-bis(pentamethylene)-1,2,3-butatriene],1

“…10 Starting with a commercially available propargylic alcohol and diethyl chlorophosphite, the allenic phosphonate is formed through rearrangement of the phosphonate ester. 10 Starting with a commercially available propargylic alcohol and diethyl chlorophosphite, the allenic phosphonate is formed through rearrangement of the phosphonate ester.…”

“…10,11 Melting points were obtained using a Fisher-Johns melting point apparatus and are reported uncorrected. All solvents were purified using standard procedures.…”

“…Synthesis of Pentamethylene Allenic Phosphonate (1): 10 Under a dry nitrogen atmosphere, 2 g (16.1 mmol) of 1-ethynyl-1-cyclohexanol in 30 mL of dry dichloromethane was added dropwise to a stirred mixture of 4.4 g (28.2 mmol) of diethyl chlorophosphite and 3.47 g (43.4 mmol) of freshly distilled pyridine. The resulting mixture was stirred for 48 h. The reaction was followed by IR and was complete after 48 h. The solvent was removed by rotary evaporator under reduced pressure.…”

α-Phosphonovinyl Carbanions in Organic Synthesis

“…The allenylphosphorus compounds 12, 14 and 16 obtained according to this method similarly undergo deprotonation with a strong base (LDA or KHMDS) at -78 °C or 60°C to give a-phosphorus-substituted allenyl carbanions 13, 12 15 13 and 17, 14 respectively (Scheme 6).…”

“…The a-phosphono-and a-phosphinoylallenyl carbanions 15 and 17 as well as a-phosphonovinyl carbanions undergo the intra- 13 or intermolecular 14 HWE reaction with the carbonyl moiety to form cumulenes 26 and 27a-c, respectively (Scheme 11 and Table 2).…”