Sodium hydride → 6-(7-Hydroxyheptyl)-7-(6-methoxy-3-oxohex-1-enyl)-1,4-dioxaspiro[4,4]nonane

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Reaction Steps

A solution of dimethyl 5-methoxy-2-oxopentylphosphonate (5.3 g.) in tetrahydrofuran (19 ml.) was added to a stirred suspension of sodium hydride (0.39 g.) in tetrahydrofuran (140 ml.). The mixture was stirred at room temperature until the evolution of hydrogen had ceased, then treated dropwise with a solution of 7-formyl-6-(7-hydroxyheptyl)-1,4-dioxaspiro[4,4]nonane [4.8 g.; prepared as described in Example 1(iv)] in tetrahydrofuran (47 ml.) and stirred for a further 2 hours. The mixture was acidified to pH 4 by the addition of glacial acetic acid, the solvents were removed in vacuo and diethyl ether was added to the residue. The solid was filtered off and the filtrate was washed with aqueous sodium carbonate, dried over anhydrous sodium sulphate, and evaporated to dryness, to give 6-(7-hydroxyheptyl)-7-(6-methoxy-3-oxohex-1-enyl)-1,4-dioxaspiro[4,4]nonane (6.4 g.), νmax 1620 cm-1, 1660 cm-1.

Provenance & Evidence