| 摘要 |
1,262,496. Alkylidene phosphoranes; olefinic esters; Vitamin A and carotene. BADISCHE ANILIN- & SODA-FABRIK A.G. 13 June, 1969 [15 June, 1968], No. 30105/69. Headings C2C, C2P and C2V. [Also in Division C5] A process for the production of olefinic compounds, including Vitamin A and carotene, comprises reacting an aldehyde or ketone with an alkylidene phosphorane which is prepared by reacting a quaternary phosphonium halide with an epoxide, particularly ethylene oxide, at a temperature of - 10‹ to 200‹ C. If desired, the alkylidene phosphorane may be prepared in situ from a trialkyl or triaryl phosphine, an organic halogen compound and the epoxide, the reagents and the aldehyde or ketone being mixed in any order. |
