The Geometry of Dienes from 2,3-Substituted-3-Sulfolenes and the Stereoselectivity of their Intramolecular Diels-Alder Cyclisations

✍ Scribed by John Leonard*; Stephen P. Fearnley; Andrew B. Hague; Gordon Wong; Martin F. Jones

• Book ID: 104256910
• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 547 KB
• Volume: 38
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(97)00546-7

✦ Synopsis

The geometryof dienesobtainedfrom2,3-substitutedsulfolenesbearinga 3-carboxyl derivativeis dependenton the natureof the 3-carboxygroupand on the functionalityof the 2substituent. These factorsthereforehavea crucialinfluenceon the stereoselectivityof subsequentDiels-Alderreactions, @ 1997Publishedby Elsevier Science Ltd.

We have been exploring synthetic routes to yohimbineand manzamine-type alkaloids involving intl"amolecular Diels-Alderreactionsof 2,3-disubstitutedsulpholenemaskeddiene precursors.l-gSuchroutes are short and effective because of the l"eadyavailability of the 2,3-disubstitutedsulpholeneprecursorsvia alkylationof the dianion of 3-carbomethoxy-3 -sulpholene1. In particular,a range of methodshave been developedforinstallingdienophileslinkedthrougha nitrogenatom(Scheme1)."4