L-Hepten

A mixture of 23.4 g (39.3 mmol) of bis[(tributyl)tin] oxide and 11.6 g (81.7 mmol) of 4,6-dimethyl-l-hepten-4-ol is heated at 220 CC for 10 h in a three-necked flask equipped with a 12-cm Vigreux column, a condenser, a thermostat, and separating funnel. During this time a further 11.6 g (81.7 mmol) of 4,6-dimethyl-1-hcp-ten-4-ol are added dropwisc, and 4-methyl-2-pentanone (approx. 16 g) distilled out. The residue is distilled yield 11.5 g (88%) bp 92-93 °C/0.3 Torr. 

B. (Z)-l-Iodo-l-heptene.2 A solution of 8.52 g of (112 mmol) of borane-dimethylsulfide complex (Note 13) in 100 mL of ether is added to a flame-dried, three-necked, 300-mL, round-bottomed flask equipped with stirbar, temperature probe, and N2 inlet. The solution is cooled to 5°C with an ice-bath. Cyclohexene (18.4 g, 224 mmol) (Note 14) is then added by syringe over 10 min while keeping the temperature below 15°C. The mixture is stirred at 5°C for 15 min. A white solid precipitates either towards the end of the addition or during the subsequent stirring period. The reaction mixture is allowed to warm to room temperature and is stirred for 1 hr. The non-homogeneous solution is cooled to 2-3°C... 

Some cyclization also occurs with the bromide, but not with the chloride or the tosylate. The secondary iodide, 6-iodo-l-heptene, gives a mixture of cyclic and acyclic product in THF.165... 

The presence of Me3Sn and Me3Ge radicals was ascertained by reactions of the lithio reagents with cyclopropylcarbinyl bromide and 6-bromo-l-heptene, whereupon products of free radical reactions were produced along with those from direct displacement. 

A reductive intermolecular Heck heteroarylation (hydroheteroarylation) of A-protected azabicyclo[2,2,l]heptene 165 has been used to construct 7-azabicyclo[2.2.1]heptane 166 in moderate yield [131, 132]. An asymmetric version of such a transformation to provide enantiomerically-enriched iV-protected epibatidine has also been described [128, 133]. It was found that introduction of Noyori s BINAP ligand resulted in the best enantioselectivities with 72-81% ee and a 53% yield. By using either the (R)- or (S)-BINAP ligand, either enantiomer was easily accessible. 

Dimethyl-l-butyne, 2408 1,8-Diphenyloctatetrayne, 3788 Hepta-l,3,5-triyne, 2641 l-Heptene-4,6-diyne, 2707... 

---