Picosecond Studies of Bacteriorhodopsin Intermediates from 11-cis Rhodopsin and 9-cis Rhodopsin

Carotenoids and polyterpenoids

“…A new preparation of y-cyclohomogeranial (330) and of dihydro-y-ionone (331) and its derivatives ( 332)-( 334), all of which are volatile components of ambergris, utilizes Claisen rearrangement of the vinyl ether (336). In the trisporic acid series, an efficient synthesis of deoxytrisporone (348) has been achieved from isobutene and methyl 2,4-dioxohexanoate by a route involving photocycloaddition and chain elongation with the lithium dianionic species (351) (which was generated from 3-methylbut-2-enoic acid and lithium di-isopropylamide),'70 methyl (7E,9Z)-trisporate B (349) has been obtained by a procedure which uses 2-(hydroxymethy1)cyclopropyl phenyl sulphide (as its lithium dianion),' and methyl 4-dihydrotrisporate B (350) has been prepared ria Wittig condensation of the lactone (352) and the triphenylphosphonium bromide (353).…”