Question

Jould th of these syntheses of l-phenylbuta-1,3-diene form the central double bond. Show w you would synthesize this target molecule by forming the terminal double bond. bonde Remer Snizat an un halide. ary and at these Solved by de PROBLEM 18-33 Show how Wittig reactions might be used to synthesize the following compounds. In each case, start with an alkyl halide and a ketone or an aldehyde. (a) Ph-CH=C(CH 2 (b) Ph-C(CH3)=CH- (c) Ph-CH=CH-CH=CH-Ph (d) H CH.CH CH;

Answer 1

Ph-CHLU, lde syntha Ph Ph- Ph-CH By + Ph Ph EtoNa Ph-Phz witfi Recutt!. ph-CHPPh3 CH3 -pph3 Ph-CH Ph CH C-h 1 Pph Ph-C Ph-CH Ph- PPhs (2. Ph- сH CCH) -BY +PPhs Ea Ph-c PPh Ph-CHPPh3 + HCHD Pn-CH-cH Ph- CHCHCH2-BY+ PPhatoNa Ph-H-Pph- Ph-CHECH CHPPh3+ H-E-Ph> ph-CHECH-CH =CH-Ph Pph3 PPhEe Na CH -сн, -CH CH