Synfacts 2005(3): 0296-0296  
DOI: 10.1055/s-2005-921583
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

[3+3] Cycloaddition Approach to the Synthesis of Substituted Pyrans and Oxapanes

Contributor(s): Victor Snieckus, Robert Engqvist
A. Al-Harrasi, H.-U. Reissig*
Freie Universität Berlin, Germany
Further Information

Publication History

Publication Date:
22 November 2005 (online)

Significance

The [3+3] cycloaddition of lithiated alkoxyallenes with aldonitrones gives enantiopure 3,6-dihydro-1,2-oxazines which are easily cyclized, in a stereocontrolled manner, into oxazine-fused pyrans and oxepanes under Lewis acid conditions.