First Syntheses of 2,2-Dimethyl-7-(2′-methylbut-3′-en-2′-yl)-2H-chromen-6-ol and 2-(3′-Methylbut-2′-enyl)-5-(2′-methylbut-3′-en-2′-yl)-1,4-benzoquinone, Novel Prenylated Quinone Derivatives from the New Zealand Brown Alga Perithalia capillaris

The first syntheses of 2,2-dimethyl-7-(2'-methylbut-3'-en-2'-yl)-2H-chromen-6-ol (1) and 2-(3'-methylbut-2'-enyl)-5-(2'-methylbut-3'-en-2'-yl)-1,4-benzoquinone (2), novel prenylated quinone derivatives from the New Zealand brown alga Perithalia capillaris, are reported, in which the key steps are consecutive Claisen rearrangements that proceed with both high chemo- and regioselectivity.