Chlorophosphonates: Inexpensive precursors for stereodefined chloro- substituted olefins and unsymmetrical disubstituted acetylenes

Abstract

New chlorophosphonates bearing a 1,3,2-dioxaphosphorinane ring which are useful for the stereospecific synthesis of 5-chlorofurfuryl substituted olefins and chloro-substituted dienes have been obtained by an easy, inexpensive route. The utility of some of these in the synthesis of ferrocenyl- and anthracenyl-substituted unsymmetrical acetylenes has been explored. The structures of the phosphonates (OCH2CMe2CH2O)P(O)CH2(C4H2ClO) (4) and (OCH2CMe2CH2O)P(O)(CH=CHCH(Cl)Ph (7) have been determined; in addition, the stereochemistry of (5-chlorofurfuryl)CH=CH(4-ClC6H4) (13b) and 2,4- Cl2C6H3-CH=CH-CH=C(Ph)Cl (14a) is unambiguously proved by the X-ray structure determination.