p-Toluenesulfonic acid → 1-Oxaspiro[4.5]dec-7-ene

Participants

Reaction Conditions

Reaction Steps

This crude 3-(1,4-cyclohexadienyl)propan-1-ol thus obtained was divided into two batches. Each batch was treated separately with 2.5 g of p-toluenesulfonic acid. The pressure was lowered to 12 mmHg and the pot immersed in an oil bath heated to 115° C. After about 0.3 hr distillation through a short vacuum jacketed vigreaux column at reduced pressure began and continued at a steady rate as cyclization proceeded. A total of 105.4 g (76% yield) of the 1-oxaspiro[4.5]dec-7-ene was obtained as a water white liquid, bp 79°-81° C. (12 mmHg). The NMR spectrum was identical to that for the same compound described in Example 1 above, step E.

Provenance & Evidence