Synthesis of naturally occurring acetylenes via an alkylidene carbenoid rearrangement.
Naturally occurring mosquito larvicidal acetylenes 1 and 2, and analogues 3 and 4, each containing either a 1,3-butadiynyl or a 1,3,5-hexatriynyl moiety, are synthesized via a Fritsch-Buttenberg-Wiechell rearrangement. The alkylidene carbenoid intermediate results from lithium-halogen exchange of a suitable dibromoolefin precursor, and the rearrangement is accomplished under mild conditions. Synthesis of the dibromoolefin precursors to acetylenes 1-4 is easily achieved in three steps from commercially available carboxylic acids or aldehydes, making this procedure a viable alternative to conventional methods for the synthesis of naturally occurring acetylenes.
Shun
Annabelle L K Shi
AL
Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2 Canada.
Tykwinski
Rik R
RR
D000114:Acetylene / Q000138:chemical synthesis* / Q000737:chemistry; D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry; D000478:Alkylation; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular
D000475:Alkenes; D007202:Indicators and Reagents; D000114:Acetylene