Photochemical Cycloaddition of Mono-, 1,1-, and 1,2-Disubstituted Olefins to a Chiral 2(5H)-Furanone. Diastereoselective Synthesis of (+)-Lineatin

The photochemical [2 + 2] cycloaddition of (S)-4-methyl-5-O-pivaloyloxymethyl-2(5H)-furanone, 5, to vinyl acetate, vinyl pivalate, tert-butyl vinyl ether, 1,1-diethoxyethylene, and (Z)- and (E)-1,2-dichloroethylene has been studied. A practical synthesis of (+)-lineatin from 5 has been developed via the functionalized cyclobutane 6.