epoxy-p-menthene,(3R,4S,8R)-3,9-epoxy-1-p-menthene synthesis

Yield:13955-48-1 79%

Reaction Conditions:

with boron trifluoride diethyl etherate in diethyl ether at 20;diastereoselective reaction;

Steps:

4.4. General procedure for the cyclisation of p-menth-1,5-dien-9-ol isomers

General procedure: A suitable acid catalyst (see Table 1) was added dropwise to a solution of the p-menth-1,5-dien-9-ol isomer (6 mmol) in dry ether (40 mL). After stirring at rt for 5-24 h (see Table 1), the mixture was quenched by the addition of aq NaHCO₃ (5% solution, 100 mL) and extracted with ether (2 × 50 mL). The combined organic phases were washed with brine and then dried (Na₂SO₄). Concentration by distillation of the solvent through a vigreux column gave an oil, which was purified by chromatography eluting with hexane/ether (95:5-9:1) as eluent to afford pure ether 7 or 8.

References:

Serra, Stefano;Nobile, Igor [Tetrahedron Asymmetry,2011,vol. 22,# 13,p. 1455 - 1463] Location in patent:experimental part