Acetates pyrolysis

Alcohols can be dehydrated via xanthate esters at temperatures that are much lower than those required for acetate pyrolysis. The preparation of xanthate esters involves reaction of the alkoxide with carbon disulfide. The resulting salt is alkylated with methyl iodide. 

The final step of this synthesis used a high-temperature acetate pyrolysis to introduce the exocyclic double bond of longifolene. 

Acetate pyrolysis is illustrated by the synthesis of penta-1,4-diene (Expt 5.14) from 1,5-diacetoxypentane. This is prepared from 5-chloropentyl acetate which is conveniently obtained from tetrahydropyran by treatment with acetyl chloride this ring-opening reaction offers interesting comparison with the methods for the preparation of a, cu-dihalides discussed in Section 5.5.1, p. 555. 

Figure 6.1.13. Pyrogram of poly(ethylene-co-vinyl acetate) 9% wt. vinyl acetate. Pyrolysis done on 0.4 mg material at 60(f C in He, with the separation on a Carbowax type column.

Neureiter, N. P. Pyrolysis of 1,1-dichloro-2-vinylcyclopropane. Synthesis of 2-chlorocyclopentadiene. J. Org. Chem. 1959, 24, 2044-2046. Overberger, C. G., Borchert, A. E. Novel thermal rearrangements accompanying acetate pyrolysis in small ring systems. J. Am. Chem. Soc. 1960, 82, 1007-1008. 

C.iv. Xanthate Ester Pyrolysis.2H 209a,b temperatures required for acetate pyrolysis... 

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