Synthesis of perhydroxazin-4-ones. Competitive Mukaiyama versus hetero Diels-Alder reaction in the cycloaddition of 2-aza-3-trimethylsilyloxy-1,3-butadiene and aldehydes
The reactions of 2-aza-3-trimethylsilyloxy-1,3-butadiene with carbonyl dienophiles are described. 2-Aza-1,3-butadienes participate as dienes in the [4+2] cycloaddition with aldehydes to afford perhydroxazin-4-ones in good yields. Experimental results, however, show that a Mukaiyama type two-step reaction must be taken into account. The cycloadducts obtained have proved to be useful intermediates in the synthesis of α-amino-β-hydroxy acids.
Bongini, Alessandro,Panunzio, Mauro,Bandini, Elisa,Campana, Eileen,Martelli, Giorgio,Spunta, Giuseppe
p. 439 - 454
(2007/10/03)
Solution phase library of perhydrooxazin-4-ones
A general approach to the solution phase parallel synthesis of perhydrooxazin-4-ones, which allows the preparation of milligram quantities of each individual member, is reported. An efficient purification method, using as 'Sequestration Enabling Reagent' (SER) aminomethylpolystyrene resin in the presence of trimethylorthoformate is also described.