Hydrochloric Acid → cis-5-Heptenamide

Participants

Reaction Steps

To a solution of 27.0 g. (52.0 mmoles) of (4-methanesulfonylaminocarbonyl-n-butyl)triphenylphosphonium bromide in 46 ml. of dimethyl sulfoxide is added dropwise 49.3 ml. (98.6 mmoles) of a 2.0M solution of sodium methylsulfonylmethide in dimethyl sulfoxide. To the resultant red solution is added over the course of 15 minutes a solution of 6.6 g. (20.8 mmoles) of the hemiacetal prepared in Example IV in 63 ml. of dimethyl sulfoxide. After being stirred for an additional 2.0 hours, the reaction is poured onto 600 ml. of ice-water. The cold aqueous layer is covered with ethyl acetate and acidified to pH~3 with 10% hydrochloric acid. The acidified aqueous layer is further extracted with ethyl acetate (2 × 200 ml.) and the combined organic extracts are washed with water followed by brine. Drying the organic layer over anhydrous sodium sulfate and concentration affords the crude product which is triturated with ether. Concentration of the ether provides N-methanesulfonyl 7-[2β-(1,3-oxathialan-2-yl)-3α -(tetrahydropyran-2-yloxy)-5α-hydroxycyclopent-1α-yl)]-cis-5-heptenamide (VI).

Provenance & Evidence