Gomerones A–C, halogenated sesquiterpenoids with a novel carbon skeleton from Laurencia majuscula

4 pages, 2 figures, 1 table, 1 scheme.-- Printed version published Nov 24, 2008.Supporting information (NMR spectra of gomerone, 13 pages) available at: http://dx.doi.org/10.1016/j.tet.2008.09.027The structures and relative sterochemistry of three halogenated sesquiterpenoids gomerones A–C, 1–3, isolated from Laurencia majuscula are described. They are representative of a novel carbon skeleton, gomerane, biogenetically derived from cyclization of a β-chamigrene precursor. A biogenetic relationship with related sesquiterpenoids from lower terrestrial plants Hepaticae of genera Bazzania, Mannia, Mylia, and Rebouli as well as higher plants of genera Cupressus and Juniperus has been established.This work was supported by the Ministerio de Educación y Ciencia (BIO2007-61745, SAF2006-03004) and DGUI Gobierno de Canarias (PIO42005, PUB2005/030)