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(±)-Vitrenal (1), a sesquiterpene aldehyde with a novel vitrane skeleton, was synthesized from a monoterpene piperitenone (2) by 12-step reactions in ca. 7% overall yield. 2-Formyl-isocarane, derived from 2 via (±)-isocaran-2-one was allylated stereospecifically and, after protection of the formyl group, the allyl chain was modified to a 4-methoxy-3-butenyl group. Acid treatment of the masked dialdehydic intermediate yielded 1 by concomitant deprotection and aldol condensation.

Three new sesquiterpenoids were isolated from the liverwort Marsupella emarginata subsp. tubulosa. The structures and absolute configurations of the compounds have been shown to be (−)-marsupellone(1), (+)-marsupellol(2) and (+)-acetoxymarsupellone(3), containing an ent-longipinane skeleton, on the basis of chemical and spectral evidence.

A novel sesquiterpene aldehyde, (−)-isobicyclogermacrenal, was isolated from Lepidozia vitrea, and its structure and absolute configuration were shown to be ent-isobicyclogermacren-14-al on the basis of the chemical and spectral evidence.