An unusual reaction course in Rh(I) - induced decarbonylation of gamma,delta - unsaturated aldehyde. Total synthesis of (+/-)- iso - beta - necrodol and (+/-) - beta- necrodol.

Decarbonylation of the y;S-unsaturated aldehydes (4 and 9), embodied in a sterically congested carbon network, with Wilkinson's catalyst followed a reaction course different from the normal decarbonylation or hydroacylation path. This investigation has led to the synthesis of iso-p-necrodol and the monoterpene p-necrodol.(I) leading to a novel methodology to the synthesis of a,a' -trans-dialkyl cyclic ethers (8). Keywords: Photosensitized electron transfer (PET), episelenonium radical cation, oxyselenylation, a,a' -trans-dialkyl cyclic ethers.been subjected to some kind of chemical or biological examination; thus vast majority of natural wealth remains unexplored. Studies on marine natural products initiated only recently have yielded molecules with exotic molecular architecture and diverse bioactivity. Well-directed research on natural products will enrich our bioresource base. In the current millennium, India is in a pre-eminent position to contribute towards natural product research with the utilization of its rich knowledge base and biodiversity.