Coelogin and coeloginin: two novel 9,10-dihydrophenanthrene derivatives from the orchid Coelogyne cristata
Abstract
Coelogin and coeloginin, two novel 9,10-dihydrophenanthrene derivatives of the high altitude Himalayan orchid Coelogyne cristata, have been shown to have the phenanthro[4,5-bcd]pyran structures (1a) and (1b), respectively, from spectral and chemical evidence.