[dielsalder]

Hi guys

I am currently reading this article: (tetrahedron, 54 (1998), 19, 4697-4753) about synthesis of shikimic acid and its analogues and i have found a stereospecific synthesis of shikimic acid from D-arabinose made by bestmann and heid. Unfortunately, i don't have access to the original article and i don't clearly understand a step in the synthesis :

''The resulting ditosylate was reacted with excess of methylenephenylphosphorane to form the ylid. Wittig reaction with formaldehyde furnished the olefin''



I don't get the 243-244 step (look like a modified wittig reaction)

here is what i have started



can someone help me with this step or to find the original article of bestmann and heid please
Thx

-Synthesis of shikimic acid and its analogues: tetrahedron, 54 (1998), 19, 4697-4753 (doi:10.1016/S0040-4020(98)00016-7)
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6THR-3W910B0-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=99653b7e03148eaed226189b7e7f7299
-Original article of bestmann and heid that i don't have access : Angewandte Chemie International Edition in English
Volume 10 Issue 5, Pages 336 - 337 (doi:10.1002/anie.197103362)
http://www3.interscience.wiley.com/journal/106578712/abstract

[Squirmy]

Do you know any other reactions of tosylates? Is there any other way to draw the methylenetriphenylphosphorane?

[dielsalder]

I only know the tosylate as a protecting agent for alcohol and amine

here is the methylenetriphenylphosphorane with his resonance 

[Squirmy]

Tosylates are also good leaving groups. Alkyl tosylates can undergo substitution or elimination.