Steteoselective Synthesis of Unsaturated Oxetanes

Ahstmct -Butynones 1 and 1 add on alkenes under UV irmdiation to afford a-alkynylaretones.The oretanes obtained wtth cyclic alkenes have been shown to hove the triple bond G o .Adducts with fumn hove been converted t o an a-vinyloretone 6 having the double bond m. 1 2 .The Paterno-Buchi reaction has been well documented far i t s synthetic and mechanistic implications.For instance, additmn of carbonyl compounds on alkenes gives oxetanes, which have been used as synthons for 1 natural product synthesis (Equation 1).