Natural acetylenes. Part XLIX. Polyacetylenes from Dahlia scapigera(A. Dietr.) Link and Otto var. scapigera f. scapigera and some Dahlia hybrids

Examination of the above Dahlia species revealed the presence of 8 polyacetylenic compounds of which the C16 ene-diyn-ene alcohol (XXXII) and its acetate were new. In representatives of the main garden varieties 36 poly-MeCH[graphic omitted]CH·[CC]2·CH[graphic omitted]CH·CH(OH)·CH(OH)·CHCH2(XVIII), MeCH[graphic omitted]CH·[CC]2·[CH[graphic omitted]CH]2·CH(OH)·CH2·CH2OH (XXVIII), MeCH[graphic omitted]CH·[CC]2·[CH[graphic omitted]CH]2·[CH2]4·CH2·OH (XXXII), Me[CC]3·[CHCH]2·CH(OH)·[CH2]3·CHCH2(XXXVI), acetylenes were detected, including the new (XVIII), (XXVIII), and (XXXVI) and their acetates. Seasonal variations of the content were noted. The C17 alcohol (XXXVI) and the C16 alcohol (XXXII) were synthesised; the latter and the corresponding C14 compound by novel routes.