Isobornyl chloride, from camphene

Formation of isobornyl chloride from camphene hydrochloride corresponds to that of pinacolin from pinacone. 

A solution of camphene (300 g) in ethyl bromide (150 g) is saturated with hydrogen chloride at 10-20° and heated under reflux for 6 days at 55°. Most of the ethyl bromide is then removed in a current of dry air, and the isobornyl chloride is filtered off and dried in a vacuum over potassium hydroxide (yield 271 g m.p. 145°). Recrystallization from pentyl alcohol gives material of m.p. 161.5°. 

In our second puzzle, we begin with exactly the same series of reactions from a-pinene hydrochloride (5.46) to camphene (5.50) that we saw in Figure 5.31. They are repeated again in Figure 5.34 to emphasise the difference between the formation of bornyl chloride (5.46) from a-pinene and the formation of isobornyl chloride (5.55) from camphene (5.50). 

The reactions of phenyliodoso dichloride and phenyliodoso chloride azide with a series of olefins including camphene (262) have been described. They react in the same way with camphene [yielding (283)], and differently from chlorine azide, which gives the isobornyl azide substituted on C-10 (284). In connection... 

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