Abstract: A search for reversible Wittig reactions of the ylides a 4 has been made by using the method of independent oxaphosphetane generation. Four pairs of diastereomeric oxaphosphetanes have been synthesized, and those corresponding to the Wittig reactions of bd with tertiary aldehyde 18 decompose to alkenes with> 98% stereospecificity. In the case of ylide a, the oxaphosphetane 2Oa-trans also decomposes without detectable ...
![5-ethyl-1,2,3,4,4a,5a,6,7,8,9,9a,9b-dodecahydrobenzo[b]phosphindole Structure](https://image.chemsrc.com/caspic/441/16523-77-6.png)
![5,5-diethylbenzo[b]phosphindol-5-ium,iodide Structure](https://image.chemsrc.com/caspic/329/113460-10-9.png)