A Convenient Preparation of Alkynols A Synthesis of A Pheromone from the Pedal Gland of the Bontebok

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Abstract
Acetylenic alcohols are important synthonsl for the synthesis of organic molecules, i n particular, the insect 2 pheroniones. They, on partial reduction give rise to either -E or olefins of high purity. The attractancy of the majority of the pheromones particularly belonging to the order Lepidoptera (moths and butterflies species) are associated with the functional moieties (acetate, alcohol or aldehyde), the double bonds (position, number and the configuration E or Z) or the length of the carbon chain. These types of compounds have been prepared1,3 earlier by alkylation of either the terniinal alkyne with the W-haloalkyl alcohol or W-alkynyl alcohol derivatives with alkyl halides using bases such as Grignard reagent, n-butyl lithium, lithium aniide etc. followed by partial reduction of the resulting disubstituted acetylenes to 6 or 1 double bonds. The most of these alkylating require protection of hydroxyl function and the yield of the alkylated products are often poor. In this communication we wish t o report a convenient method for the preparation of disubstituted acetylenic alcohol. Our method i s based on the alkylation of dianion of 4-pentyn-1-01 prepared i n situ from tetrahydrofuryl chloride and lithiurn anide i n liquid ammonia.