10-Chloro-10, 9-(epoxyalkano)selenoxanthenes (12, 14-17) were prepared by the reaction of 9-(hydroxyalkyl)-selenoxanthenes (4, 9-11) with N-chlorosuccinimide, and 1-chloro-1-phenyl-3H-2, 1-benzoxaselenoles (32-34) were similarly synthesized. The selenurane structure of 14 was established by X-ray analysis. The proton nuclear magnetic resonance and electron impact mass spectral data supported the selenurane structures of these compounds. Reactions of the selenurane 16 with sodium acetylacetonide gave a selenoxantheniomethanide derivative 37. Thermal reaction of 14 provided 9-(1-chloro-2-hydroxyethylidene)selenoxanthene (41) together with 9-(2-hydroxyethyl)selenoxanthene (9), while thermal reaction in ethanol produced 9-(1-chloro-2-hydroxyethyl)-9-ethoxyselenoxanthene (42). On the other hand, the benzoxaselenole selenurane (32) was heated at 195-200°C to afford 2-(phenylseleno)benzyl chloride (45), 2-(phenylseleno)benzyl 2-(phenylseleno)benzoate (46) and 2-(phenylseleno)benzaldehyde (28).
Stable selenoxanthenium ylides : synthesis and new reductive cyclization of selenoxanthen-10-10(alkoxalyl alkoxycarbonyl)methanides and their related compounds
作者:Tadashi Kataoka、Kiminori Tomimatsu、Hiroshi Shimizu、Mikio Hori
DOI:10.1016/s0040-4039(00)81331-3
日期:1983.1
alkoxycarbonyl)methanides were prepared from the corresponding selenoxides and activated acetylenes. In the reaction of 9-phenylselenoxanthene 10-oxide() with methyl propiolate afforded an unexpected product, methyl 9-phenylselenoxanthen-9-ylpropiolate() together with ylide(). The selenonium ylides underwent new reductive cyclization with sodium borohydride to afford new cyclicselenonium ylides.